Carl Ekern, Ram player representative, and Gary Jeter, team alternate, exchanged heated words after Wednesday morning's picketing session outside Rams Park in Anaheim.
One source said Jeter removed his shirt and appeared ready to trade blows with Ekern.
Ekern, reached Wednesday night, confirmed the confrontation took place but would not elaborate. Jeter could not be reached for comment.
A Ram player, who asked not to be identified, said Ekern and Jeter have disagreed about the team's philosophy regarding the current National Football League players strike. Jeter is considered to be a hard-line union man while Ekern is perceived to be more passive toward strike-breakers.