Fans are speculating that Anthony Martial might not be over the club's decision to hand his No 9 shirt to new signing Zlatan Ibrahimovic.
In true 21st century shade-throwing style, the 20-year-old has changed his cover photo and profile picture on Facebook to images of him that prominently display the number nine.
The eagle-eyed among them also noticed that Martial doesn't follow Manchester United on his social media accounts.
Yesterday, Martial changed his Facebook DP twice, with No 9. And unfollowed Man Utd on Twitter and IG. Rebellion? pic.twitter.com/ok2ZMUBvXg
-- Chidi Okereke (@Chydee) July 24, 2016
Some think it's all a bit silly.