#3 Neymar (PSG)
It might seem shocking to include the world's most expensive player on this list, especially given how well he's performed since joining PSG, but there is a growing number of people who think that the Brazilian will spend only one season in the French capital.
The attacker's statistics are ridiculous: 19 goals and 13 assists in the league as well as 6 goals and 3 assists in their UEFA Champions League campaign. Yet that campaign ended prematurely, at the last-16 stage against Real Madrid, and the desire to win this competition was the primary reason behind him joining the club.
The league was always likely to be PSG's to lose and this has continued to be the case, but the challenge in France isn't enough for a player with his talent. It was always going to be a risk moving to the club in the hopes of winning European club football's biggest trophy, for PSG are still a work-in-progress.
Kylian Mbappe, Edinson Cavani, and Adrien Rabiot are world-class players but Unai Emery isn't good enough a coach to put it all together into a cohesive unit. The ability of those on the pitch is good enough to easily help PSG stroll past the French league, but against Real Madrid, they were deservedly beaten over both legs.
Coincidentally, it's this same club that most think Neymar will join, and the talk about a move to Madrid hasn't ceased since he moved to France. With Cristiano Ronaldo ageing, it might be the perfect time for Neymar to succeed him as the leader of their attack.
It would also, crucially, pit him directly against Lionel Messi, the man he hopes to succeed as the world's best player. It will take another world-record transfer fee to remove him from the club he's only just joined, but Zidane and Madrid would be fools not to try.