Messi is my #1 candidate. Won the league title and was the top goalscorer of La Liga and Champions League, he also has the chance of winning the league cup tomorrow, and is close to winning the European Golden Boot...The guy literally carried Barcelona on his back this season with outstanding performances. Plus, he'll also play in the Copa America, if he wins this trophy, he'll 100% win the Ballon d'Or.
There's also van Dijk. Key player in Liverpool, with a lot great performances throughout the season. If he wins the CL and also the UEFA Nanations League, then it's very likely that he'll be a strong candidate.
Last but not least, there's Mané, pretty good 2nd half of the season with some poor performances here and there. Also Salah, but same as Mané, decent first half of the season, 2nd half was better, both finished as top goalscorer of the EPL...If both win the CL, one of them will probably enter the top 3 nominees but will probably not win it if van Dijk and Messi are also among the top 3.
Btw, some of you are saying Mbappe? is this for real or are you guys just joking? I can't tell