West Ham have confirmed defenders Anton Ferdinand and Elliott Ward squared up to each other in training on Saturday.
Ferdinand took exception to Ward's cheeky slap on his head and responded by aiming a kick at him.
The pair continued to feud which resulted in Ward throwing a bottle at Ferdinand, although The Hammers have played down the severity of the bust-up.
West Ham have stated tensions are high ahead of next week's FA Cup final against Liverpool and that it is natural for players to be on edge.
"Yes, there was an incident during training which ended with Elliott throwing a plastic bottle at Anton," a club spokesman told the News of the World.
"Training sessions are highly competitive, especially with the FA Cup looming and players fighting for their places.
"It couldn't have been that bad because after training both Elliott and Anton sat together eating lunch."