RE: Player Power.
I believe both the coach and the players have certain powers and it all depends on how valuable one is to the club owners.
You can site the instance of Paul Pogba and Jesse Lingard for player power as well as Mikel Arteta and Antonio Conte for coach power. Arteta had chased off over 10 players from arsenal -Aubameyang, most recently, Ozil, Mustaphe, Guendouzi, and many more - and you remember Conte's debacle with Diego Costa. It all depends if the owner backs the coach or prefer the player's point.
If the rot is deep then most likely the club might want a change of manager to help instill discipline but if it's just one or two players and the club is firm, then they'll suffer the consequences.