Aston Villa boss Martin O'Neill and midfielder Nigel Reo-Coker were reportedly involved in a sensational bust-up at the club's Bodymoor training ground on Thursday, with the manager sending the player home when he arrived on Friday.
O'Neill and Reo-Coker had to be separated by shocked players following a heated altercation during training, although no punches were thrown and O'Neill said they had not grappled each other, as had been reported.
Reo-Coker was due to arrive for training on Friday, but the Irishman sent him home, meaning he has been dropped ahead of the weekend's match against Portsmouth at Villa Park.
The manager told the club's website: "There was a mishap on the training ground. It's a common occurrence between players but on this occasion, unfortunately, it was between the manager and a player.
"There was a bit of a contretemps and that is unfortunate. Nigel didn't train this morning and obviously won't play tomorrow. I have dealt with the issue how I see fit and that's the end of it. Come Monday, we're back to normal again. I am the custodian of this place - my rules apply."
The midfielder has made no secret of feeling home sick in Birmingham and had been widely tipped to leave Villa Park during the transfer window, with Tottenham Hotspur and Fulham reported to be interested.
Reo-Coker has also been unhappy at being regularly played out of position at right-back, while he has been left visibly unimpressed by being substituted in the past two games.