Queens Park Rangers winger Eduardo Vargas allegedly refused to come on as a substitute during his team's 3-1 defeat at Crystal Palace in March.
The Chilean repeatedly resisted manager Chris Ramsey's attempts to have him replace Shaun Wright-Phillips with five minutes remaining, according to The Mirror.
QPR have confirmed that Vargas was fined over the incident, but declined to comment further.
Vargas's teammate Joey Barton allegedly identified him as one of the "bad eggs" that he believes are to blame for the team's relegation from the Premier League.
The outspoken midfielder is also said to have assigned blame to Mauricio Isla, Mauro Zarate, Adel Taarabt and Armand Traore.
Vargas is on loan at QPR from Napoli, and is expected to return to Italy in the summer.
