Aston Villa midfielder Nigel Reo-Coker has been sent home from training today for disciplinary reasons, manager Martin O'Neill has revealed.
Reports have indicated O'Neill and Reo-Coker had a disagreement in training yesterday.
When Reo-Coker arrived for training this morning, he was told to stay away until Monday.
O'Neill said: "There was a confrontation between Nigel and myself. It usually happens between players really.
"There were no fisticuffs. There was no wrestling to the ground as reported in one newspaper. That was a figment of the onlookers' imagination.
"There was enough for me to treat the incident seriously enough. Nigel will not play against Portsmouth and come Monday it will be forgotten about.
"I make the rules. I am the manager and custodian of the football club so my rules apply. Players have to get used to my rules. It's as simple as that."
The bust-up could not have come at a worse time for former West Ham midfielder Reo-Coker.
Having spent most of last season playing out of position at right-back, he had just worked his way back into his favoured central midfield position.
He was linked with a move to Tottenham earlier in the summer and this clash with O'Neill will undoubtedly cast a doubt over his long-term future at the club.