Burton Albion manager Paul Peschisolido said midfielder Jacques Maghoma has been punished after engaging with fans in an abusive rant on Twitter.
The comments came after Maghoma complained about not being selected to start for the Brewers against Plymouth on Saturday.
Peschisolido did not reveal what Maghoma's punishment was.
He told BBC Radio Derby: "He's accepted it was stupid. He's made an apology and we've dealt with the matter in house."
Peschisolido said: "I can assure you he won't be doing that again.
"You've got to learn from your lessons and I'm sure Jacques will have learnt from this one."
Burton chairman Ben Robinson said: "He said some totally inappropriate things and was very offensive. That is not the way we expect a Burton Albion player to express themselves.
"All the players were instructed by the manager that they've got to be very careful what they say on social networking sites.
"Players represent the club at all times."
The 24-year-old, who came through the youth ranks at Tottenham, issued an apology via Twitter after the comments: "If I offended anyone last night then I apologise. Wasn't meant in any harm whatsoever. Apology to all the fans and all my followers."
Burton lost Saturday's League Two match 2-1 and face Bradford away on Saturday.