Without even reading other people's posts.
*Assuming we sell Maguire and McFred
1. Sancho: I think people have had it with him especially because there's a Garnacho breaking through and Sancho's own lack of aggression in his play, which the CAF loves. If he starts the season poorly, especially if Rashford goes through a bad patch and Sancho doesn't step up then I can see it getting really toxic for him around here.
2. Antony: Especially if Amad isn't sent on loan. Didn't have the best first season and he's had the usual stock defence trotted out for him, "New league", "New team", "Young player" etc. Those quickly turn toxic when there's a new kid on the block who the fans are excited to see what he can offer. Expect there to be calls for ETH to bench him if he doesn't hit the ground running.
3. Martial: I don't suppose he will play much due to his constant injuries, but whenever he does - and especially if we don't win - there will be pages in his thread of the same people recycling why they "Can't stand him" and want him out".