Who will replace Rosberg at Mercedes?

This week Mercedes has found itself in an unusual situation as it looks to replace reigning world champion Nico Rosberg for next year. Most of the grid is locked into contracts for 2017 -- and in some cases beyond -- making finding a replacement potentially complicated and expensive. What's more, Rosberg had been at the team since it first ran under the Mercedes name in 2010, meaning he not only leaves an empty cockpit but also a huge gap in the team's engineering department. A replacement will not only have to be quick, but also a team player capable of working at the very highest level. And that's before we even mention the huge mental task of going up against Lewis Hamilton, arguably the greatest talent on the F1 grid today.

Mercedes' team management will meet in Brackley on Monday to discuss its choices, so here is a look at some of the potential candidates.

The obvious choice

Pascal Wehrlein
Although he has only driven one season in Formula One, Wehrlein has completed more test days in Mercedes Formula One cars than any other driver this year (including Rosberg and Hamilton). He has been Mercedes' go to guy for both in-season tests and 2017 tyre development tests and has a good working relationship with the team. Two years ago he won the competitive DTM championship with Mercedes, proving he has the right mindset to fight at the front and the pace to beat some of the best drivers outside F1. Yet when it came to Force India deciding on a replacement for Nico Hulkenberg earlier this year, the Mercedes-powered team chose Wehrlein's Manor teammate Esteban Ocon for 2017. Both Wehrlein and Ocon had tested with the team previously and the latter was considered to be the easier to work with as well as showing the greater long-term potential. That decision inevitably led to some soul searching for Wehrlein, but a Mercedes drive next year would be the ultimate opportunity to prove his doubters wrong. It would be a leap of faith for Mercedes, but it is in the best position to make a well-educated decision after gathering reams of data on Wehrlein during testing this year.

The fans' favourite

Fernando Alonso
The prospect of pairing Hamilton and Alonso in one of the best cars on the grid is a tantalising prospect for all F1 fans. They were teammates at McLaren for a single, explosive season in 2007, but their tense relationship led to a falling out between Alonso and team boss Ron Dennis. Speaking to ESPN earlier this year, Alonso said it "would be very different" if he was paired with Hamilton now, but would Mercedes really be willing to take the risk? Hamilton versus Rosberg proved hard enough to manage over the past three years, so Hamilton versus Alonso could prove catastrophic for the team. In the unlikely event Mercedes did push ahead with the dream/nightmare pairing, it would have to prize Alonso from his current McLaren-Honda contract. Many believe Alonso has exit clauses built in to his deal if such an opportunity should arise, but the reality is likely to be messier than that. It would be a sensational story, but don't build your hopes up.

An escape route for a four-time champion

Sebastian Vettel
Vettel is committed to a Ferrari contract next season, but there have been signs this year that the driver/team relationship is on edge. Above all, the results that both sides desired have not materialised and there are few signs that an up-turn in form is just around the corner. Technical director James Allison left earlier this year, meaning the new Ferrari dream team Vettel had hoped to build when he joined in 2015 is missing one of its key components. Ferrari has also sent a couple of warning shots towards its star driver this year, with team boss Maurizio Arrivabene saying Vettel must "earn" a contract renewal beyond 2017. Some people in parent-company Daimler would no doubt welcome a German four-time world champion at their team, but -- just as there is with Alonso -- there is a danger the strong-willed 29-year-old would unsettle the ship alongside Hamilton. It's another very unlikely choice.

The rising star

Esteban Ocon
Ocon only has half a year of F1 experience behind him, but he has made a big impression in that time. Driving for Manor at the back of the grid he was unable to score a point this season, but it was his ability to take the fight to teammate Wehrlein that really impressed. As things stand he has been rewarded with a Force India seat for next year, but as a Mercedes-contracted driver a further upgrade is not beyond the realms of possibility. He is highly-rated within Mercedes' hierarchy, although the main question is whether it would be too much, too young for a talent that clearly has the potential to go all the way to the top if nurtured in the right way. On the other hand, he beat Max Verstappen to the F3 title in 2014, so Mercedes may feel that whatever Max can do in F1, Esteban can do better.

A safe pair of hands

Valtteri Bottas
With Wolff a part of his management team, Bottas would seem like a straightforward solution to Mercedes' Rosberg-shaped problem. He is a proven points scorer -- if not race winner -- and clearly has the ability to deliver the consistent results that constructors' championships are made of. He is apolitical and therefore unlikely to upset the team, but perhaps doesn't quite have the star quality Mercedes is seeking. Last year he was linked to a move to Ferrari, but ultimately didn't have the edge the team felt he needed to replace Kimi Raikkonen. For all the people in the paddock who feel he deserves a chance at a top team in Formula One, it seems there are as many who remain unconvinced.

The one that got away

Max Verstappen
Back in 2014 Mercedes tried to sign Verstappen to its driver development programme but ultimately couldn't place him in a Formula One seat. Red Bull could, and for that reason he raced for Toro Rosso in 2015 and became the youngest F1 driver in history. This year he was promoted to the senior Austrian-owned team, where he is not only seen as the future of Red Bull but also F1. As much as Wolff would love to get one over on rival team boss Christian Horner by luring him away, both Red Bull drivers are contracted through to 2018 and extremely unlikely to be allowed to leave.

The ultimate partner to Hamilton

Daniel Ricciardo
For the reasons mentioned above, Ricciardo would need to pull of a Houdini act to release himself from his Red Bull contract. But in a hypothetical scenario where every driver on the F1 grid was free to move where he liked, the Australian would surely be at the top of Mercedes' list. A proven race winner who is both hungry enough to win world titles and easy going enough to coexist with Hamilton, Ricciardo ticks every box. But Red Bull knows more about those qualities than anyone else and would be mad to let him go to a main rival. What's more, who's to say Red Bull won't be a better championship prospect than Mercedes next year.

A surprise return

Jenson Button
For most of the last few races of the season it appeared as though Button was content in his decision not to drive in Formula One next year. Then came a slight moment of doubt in Abu Dhabi. Perhaps such things are normal for a driver leaving the sport he dedicated so much of his life to, or perhaps he would be open to a surprise return in 2017. Mercedes is, after all, the team he won his title with in 2009 and many of the same people are still working in Brackley today. As unlikely as it seems, Button could offer a one-year solution that would allow the British driver to end his career on a high as contracts elsewhere expire.

An overlooked talent

Carlos Sainz
A product of Helmut Marko's sink-or-swim junior programme, Sainz looks like he could be one of the rare few who leave Toro Rosso for a team other than Red Bull in F1. He was high on Renault's list this year, but Red Bull were unwilling to let him go and he remains contracted to Toro Rosso for another season in 2017. However, there is a limit to how long Red Bull can hold back his talent and an offer from Mercedes might just be enough to tip the balance. On the basis of his performance in an under-powered car this year and his performance as Verstappen's teammate last year, he certainly wouldn't embarrass himself in a race-winning team.

Another Nico

Nico Hulkenberg
It seems as though Hulkenberg has been on the shortlist for a top drive in F1 at every point in his career. For 2017 he has secured a manufacturer drive with Renault, which is a great long-term opportunity but not one that is expected to deliver wins in the next two seasons. But when you look at the other talent on this list, it seems unlikely that he would feature at the very top of Mercedes' wishlist, especially as it would require the unpicking of a newly-signed two-year contract.