The coronavirus pandemic has made the transfer market uncertain -- and you can find out when the windows open and close here -- but here are the rumours floating around Europe's big leagues and beyond.
TOP STORY: Man City prepare new Koulibaly bid
Sky Sport Italia's Gianluca Di Marzio reports that Manchester City are ready to submit a new bid for centre-back Kalidou Koulibaly. The saga of the great Napoli defender's future seems to be on the verge of coming to an end, and that end could well take him from Serie A to the Premier League.
Napoli president Aurelio De Laurentiis hasn't been afraid to put forward his thoughts on how negotiations are going, and City are set to react to that. The offer will be in the range of at least €75 million as Pep Guardiola aims to edge ahead of rivals Manchester United in this particular transfer race.
22.30 BST: Will Real Madrid shed Luka Jovic? According to Calciomercato, AC Milan execs Paolo Maldini and Frederic Massara meet with the players' agent to discuss bringing in the Serbian on a loan.
21.00 BST: Portuguese club Sporting CP are interested in Luis Suarez -- but not the one you may be thinking. This one is the Watford striker, who spent last season on loan at Zaragoza.
With Watford relegated back to the Championship, the club are looking to raise funds and Lisbon-based Sporting may swoop in for the Colombian player, according to Sport.
Meanwhile, the more known Suarez remains on the verge of a move from Barcelona to Juventus, and trained separately from the Catalan squad ahead of the move.
20.15 BST: It may not reach the level of Messi and his U-turn to remain at Barcelona, but PSG keeper Sergio Rico has decided to stay put in the French capital. The Ligue 1 champions announced that Keylor Nava's backup will remain in Paris after an agreement with parent club Sevilla FC was reached.
Rico played in quarterfinal and semifinal rounds of PSG's Champions League run this past season while Navas had sat out with the injury.
The deal for the 27-year-old Spanish shotstopper is for four years. There will now be questions about the future of French keeper Alphonse Areola, back in Paris after a season's loan at Real Madrid.
19.45 BST: Nottingham Forest have joined Norwich City in the race for Paris Saint-Germain's young defender Loic Mbe Soh, Goal reports. The France U-20 man, whose contract with PSG expires in 2021, has also been linked to moves with other Ligue 1 clubs, including Bordeaux.
18.17 BST: Wolves have completed a club record signing deal for Portuguese teenager Fabio Silva from Porto.
The 18-year-old striker has put pen to paper on a five-year contract at Molineux.
The club announced that it was a club record transfer and the fee has been reported at £35m.
Introducing...— Wolves (@Wolves) September 5, 2020
17.07 BST: Bayern Munich midfielder Thiago has dismissed reports linking him with a move away from the club this summer.
Sources have told ESPN that the Spain international has been a target for Premier League clubs Manchester United and Liverpool but he said he is focused on his football.
"I have not told anyone that I am leaving," he told a news conference ahead of Spain's UEFA Nations League clash against Ukraine. "Every year you put me in a different club.
"For me my future is tomorrow's game and there is nothing to discuss on this. I neither care nor am I interested. My interest is in tomorrow's game."
16.11 BST: Don't forget to take a look at ESPN's Insider Notebook. There's plenty of transfer news to follow, including:
- Manchester United boss Ole Gunnar Solskjaer has told executive vice-chairman Ed Woodward to value dressing room harmony over transfer business as the club continue to deal with the fall-out from Alexis Sanchez's disastrous move, sources have told ESPN's Rob Dawson.
- Real Madrid are considering a second round of temporary wage cuts for players as the club assesses the long-term financial impact of the coronavirus pandemic, sources have told ESPN's Alex Kirkland and Rodrigo Faez.
- Atletico Madrid are yet to receive an offer for Arsenal target Thomas Partey, sources told ESPN, with PSG now in the running to land the midfielder.
15.22 BST: West Ham United captain Mark Noble was not happy after the club announced that youngster Grady Diangana joined West Brom on Friday.
Noble expressed his anger on Twitter while fellow teammate Declan Rice liked the post.
As captain of this football club I'm gutted, angry and sad that Grady has left, great kid with a great future!!!!! https://t.co/oNPPEp8Pt6— MARK NOBLE (@Noble16Mark) September 4, 2020
West Ham midfielder Jack Wilshere replied to Noble's post and said: "Go and do your thing in a club that respects you. Big player with a big future."
Diangana, 22, signed a five-year deal with the newly promoted Premier League club after an impressive loan spell last season.
14.30 BST: United States men's national team under-17 international Zach Booth has signed with Leicester City, the club announced on Friday.
Booth, whose older brother Taylor plays with Bayern Munich's reserve team, first caught the eye of Leicester in February, when he was playing with the U.S. U-17s in a tournament in England. Booth had been linked with Tottenham Hotspur, but when the Foxes expressed their interest -- helped by the fact that the player holds an Italian passport -- Booth was impressed with what he saw.
"It was just a really good first impression with the club and the players and the coaching staff," Booth told ESPN. "I just really enjoyed it from the start."
Booth counts former Barcelona midfielder Andres Iniesta as his favorite player to watch growing up, and he feels that his best position is in the center of midfield. But it was older brother Taylor who proved to be even more of an inspiration when he signed with the Bavarians.
"[Taylor] paved the way for me, definitely," he said. "He's the one that made me want to come over overseas. He gave me that drive. I just saw what it took to come over [to Europe], how hard he had to work, and I just kind of followed."
13.58 BST: Luis Suarez and Arturo Vidal trained separately from their Barcelona teammates on Saturday, sources have told ESPN, as both players prepare to leave the club.
ESPN reported on Friday that Suarez, 33, had agreed to join Juventus while Vidal, also 33, is in talks with Inter Milan (see 10.50 BST).
New Barca manager Ronald Koeman decided that the pair should train individually, accompanied by a fitness coach, rather than join the rest of the squad.
Both players were informed in brief conversations with Koeman last week that they were not part of his plans next season as Barca look to rebuild their squad after a disastrous 2019-20.
Suarez, who has risen to third in Barca's all-time goal-scoring charts since joining in 2014, is expected to move to Turin for a nominal fee.
Sources told ESPN that Vidal had originally been expected to stay at Camp Nou but there was a change of heart after the 8-2 Champions League quarterfinal defeat at the hands of Bayern Munich. He is now likely to link up with his former coach at Juventus, Antonio Conte, in a return to Serie A.
13.26 BST: Manchester United's Dean Henderson established himself as one of the Premier League's best goalkeepers during his loan spell at Sheffield United. With a starting spot for England at a major tournament next summer up for grabs, can he afford to spend the season battling with David De Gea for the No. 1 spot at Old Trafford?
12.49 BST: Arsenal have re-signed Real Madrid midfielder Dani Ceballos on loan, the club announced on Friday.
The 24-year-old spent the 2019-20 season with Arsenal and made clear that he wanted another season with the north London side.
Sources told ESPN that Mikel Arteta had been in regular contact with Ceballos during the summer break and it was a combination of that and his friendship with a number of his teammates that convinced him to stay with the Gunners.
Ceballos impressed in the second half of the 2019-20 campaign, ending the campaign with 24 league appearances and starting in the FA Cup final win over Chelsea last month.
12.08 BST: Newcastle United and Aston Villa have both made bids to sign Bournemouth striker Callum Wilson on Saturday, according to Sky Sports.
Newcastle reportedly lodged a £20m offer with the relegated Cherries, before Premier League rivals Villa raised their proposed fee to £21m.
Wilson scored 41 goals in 126 league appearances during Bournemouth's five years in the Premier League, and now wants a return to the top flight to resurrect his England career.
Sky reports that the 28-year-old favours a move to Newcastle, who could potentially let midfielder Matt Ritchie move in the other direction.
11.32 BST: Chelsea signed Kai Havertz from Bayer Leverkusen on Friday, the club's sixth major arrival ahead of next season after Hakim Ziyech, Timo Werner, Ben Chilwell, Malang Sarr and Thiago Silva.
According to ESPN sources, Chelsea agreed to a fee of £62m that could rise to £71m despite Bayer initially holding out for a fee closer to £90m.
It's big money for a 21-year-old, but the deal earns Chelsea an 'A' in our grades of all the biggest transfers this summer.
10.50 BST: Barcelona striker Luis Suarez has agreed to join Juventus, sources have told ESPN.
ESPN reported earlier this week that Italian champions Juve were in talks to sign the 33-year-old Uruguay international but expected a deal to be "difficult."
However, Suarez, who is the third-highest scorer in Barcelona's history is now set to depart for Serie A with reports claiming he will move for a nominal fee and link up with Cristiano Ronaldo in Turin.
Suarez would join Arthur at Juventus, the midfielder agreed a switch to Italy before the season ended, while Ivan Rakitic has also left Barcelona this week.
10.09 BST: Everton have confirmed the signing of Brazil international midfielder Allan from Napoli on a three-year contract for an undisclosed fee reported to be around £25m.
Allan, 29, reunites with Carlo Ancelotti at Goodison Park after playing under the coach during his time in charge of the Italian club.
"It is a real pleasure to sign for Everton," the 2019 Copa America winner told the club's website. "I am immensely happy to be here.
"I hope, like I have done in my entire career, I contribute with my performances together with my teammates and that I put in some great games, great performances and win important things.
"It is a club with a rich history in the Premier League, has real ambition and then there is Professor Ancelotti. He has done everything possible to bring me here. It is the size of the club and the name of the coach which means you don't think twice about coming to Everton."
09.44 BST: Manchester United's hopes of making a breakthrough in their attempts to sign Jadon Sancho hinge on reaching a compromise over wages and agent fees, sources have told ESPN.
United continued to work on a deal for Sancho while also securing the services of Ajax midfielder Donny van de Beek. He became Ole Gunnar Solskjaer's first signing of the summer when he was unveiled on Wednesday.
Sancho remains the club's top summer target but fees requested by agents and intermediaries, plus Sancho's wage demands, continue to be a stumbling block.
United have also told Borussia Dortmund they believe their €120m valuation is "unrealistic" during the coronavirus pandemic but are willing to put together a structured payment plan if progress with Sancho's representatives can be made.
The decision, announced in a video interview published by Goal.com, comes after days of intense speculation sparked by Messi's attempt to unilaterally rescind his contract on Aug. 25. Messi and his legal team argued on Friday that he had exercised a clause that enabled him to leave without financial penalty at the end of each season.
"I would never take the club I have played my entire life for to court, and that is why I am staying in Barcelona. It was a tough decision. I always said I wanted to end my career here and I do," Messi said.
Barcelona has said the exit clause expired in June and that Messi's deal -- which runs until 2021 -- is still valid. They claimed that if Messi wanted to leave, he or his next club would have to pay his €700m release clause or face legal action.
La Liga backed up Barca's position, saying they would not process Messi's transfer unless his buyout clause was paid. That stance was criticised by Messi's father, Jorge, in a letter sent to La Liga on Friday, insisting that the €700 million fee was no longer applicable.
PAPER TALK (by Harry Kettle): Milan reach Bakayoko agreement with Chelsea
The two clubs have reached an agreement for the 26-year-old to move to the San Siro for the season for €3m, with the Rossoneri possessing a €30m option to purchase next summer.
Milan are in the midst of reshaping their midfield, with the seven-time European champions expected to confirm the signing of 20-year-old Brescia prodigy Sandro Tonali in the coming weeks.
Sampdoria make contact with Silva
After 18 months on loan with Monaco he was hoping to complete a permanent transfer to the Ligue 1 club, but with an offer yet to emerge from the Principality, Ranieri is looking to strike.
Silva admitted earlier this summer that his future probably lies away from the King Power Stadium, and with just one year remaining on his contract, it's difficult to envision any other outcome.
- West Ham United have made a bid of more than £20m for Burnley centre-back James Tarkowski, Sky Sports reports. The story comes in the wake of the news that Grady Diangana, an England U21 international within the Hammers' ranks, was sold to West Bromwich Albion. David Moyes ensured fans that the money made from the sale would be reinvested into the squad, and if they're able to land Tarkowski, he'll go some way towards following through on that claim.