Oldham midfielder Ritchie Jones was ordered home by player-manager Paul Dickov prior to Saturday's 1-1 draw at Yeovil.
The 24-year-old reacted after being told he was not in the team and, after leaving a pre-match training session, was put on a train home.
A club statement said: "Disciplinary action taken by the manager has been endorsed by Latics' directors.
"The matter will be discussed further with the manager in the near future."
Jones was signed by Dickov on a free transfer on a two-year deal last summer following his release by Hartlepool.