Scouting spotlight looks at a possible replacement for Laurent Koscielny at Arsenal, a Lyon full-back tipped to become successor to Jordi Alba at Barcelona and a Sevilla defender reportedly interesting Jose Mourinho.
Abdou Diallo -- Mainz
A product of Monaco's youth academy, Diallo joined Mainz for around €5 million last summer. He has settled quickly in Germany, helping his new club maintain their Bundesliga status with a string of impressive performances.
Diallo is one of those rare gems in defence: a left-sided centre-back who gives balance to the back line. He ticks a number of boxes for prospective suitors, displaying excellent technical ability, strength in the air, and the pace to drive speedy attackers away from goal.
The 22-year-old is confident with the ball at his feet, looking to play probing passes into the final third, and has the composure to hold on to possession if his options are limited.
Diallo's leadership qualities have also been recognised by his appointment as France under-21 captain, with the youngster exuding a maturity that belies his years.
With 27 Bundesliga appearances in his debut campaign, along with three goals that contributed to an additional five points, Diallo has played a vital role in Mainz's survival.
He started at left-back in Saturday's 2-1 win away to Borussia Dortmund -- Mainz's third victory in four games -- restricting the impact of Mario Gotze and Christian Pulisic on the hosts' right flank with an assured performance.
Diallo's influence is highlighted by Mainz winning only one of the six Bundesliga matches he has missed this season, with the club now facing a battle to hold on to the defender.
Where would he fit in?
Diallo has reportedly been earmarked for a summer move to Arsenal by the club's German head of recruitment Sven Mislintat. He would certainly provide competition in a Gunners defence that could be without the injured Laurent Koscielny until November.
Ferland Mendy -- Lyon
There were a number of clubs chasing Mendy last summer, but he eventually joined Lyon from Le Havre in a deal worth €6m. Following a slow start, he has forced his way into the first team to play an important role in Lyon's bid to reach the Champions League.
An attacking full-back, Mendy loves to get forward down the left flank. He possesses the speed and dribbling ability to drive past defenders, and looks to pick out teammates with driven, low crosses into the box.
The 22-year-old is careful in possession, playing short passes into midfield as he waits for the opportunity for a quick exchange that allows him to exploit the space beyond his opposing full-back.
Mendy is a tenacious competitor, but he can occasionally go to ground too easily, resulting in reckless challenges.
Mendy demonstrated his attacking qualities with two assists in Lyon's 3-0 win over Troyes at the weekend, taking his tally to five for the season.
He picked out Bertrand Traore with a perfect cross for the forward's second goal, before finding Maxwel Cornet's run with a brilliant chipped pass to wrap up the victory.
Mendy has played every minute of Lyon's current eight-game winning run, which looks destined to end in Champions League qualification.
Where would he fit in?
There was Premier League interest in Mendy last year, with Brighton, Crystal Palace and Watford all tracking the left-back, but it now seems he could be set for bigger things.
Barcelona were reported to be monitoring his progress in March, with Mendy being lined up as a potential long-term successor to Jordi Alba.
Clement Lenglet -- Sevilla
A €5m signing from Nancy in January 2017, Lenglet quickly established himself in the first team at Sevilla. With reports that he has caught the eye of Europe's elite clubs, he could be on the move again in the summer.
An imposing, left-footed centre-back, Lenglet looks destined for a career at the top level. Among his greatest attributes are his positioning sense and ability to make well-timed challenges when faced with forwards driving towards goal.
The 22-year-old is aggressive in his defensive duties, sticking tight to opponents and rushing them into making poor decisions.
He is composed in possession, often carrying the ball out of defence, and can be a threat at set pieces owing to his strength in the air.
It has been a challenging season for Sevilla in La Liga, but Lenglet's reputation has grown largely due to his performances in the Champions League.
The former France under-21 international had an influential role in clean sheets against Manchester United and Bayern Munich before Sevilla exited the competition at the quarterfinal stage.
Following nine matches without a win in all competitions -- a run that brought the end of Vincenzo Montella's reign -- Lenglet played a vital part in a 1-0 win over Real Sociedad at the weekend.
The Andalusian side host Real Madrid on Wednesday with only three games left to secure an unlikely European place.
Where would he fit in?
Jose Mourinho was reportedly impressed by Lenglet's performances against Manchester United, instructing his scouts to take a closer look at the defender.
Manchester City and Barcelona have also been linked with a player who is surprisingly yet to win his first cap for France.