An argument is reported to have broken out between the manager and striker over the players' Christmas party after the 2-0 defeat at Arsenal.
Pulis was believed to have ordered the players to report for training on Monday, prompting Beattie to object after it had previously been agreed the first team would not be required to come in until Tuesday because they were due to go out in London on Sunday night for their Christmas party.
Pulis was said to have reacted furiously to Beattie's response and, after squaring up to the 31-year-old, it was alleged the pair clashed and punches were thrown.
The club refused to comment on the incident on Monday morning but confirmed the players were expected to report for training.
It was unclear whether the party had taken place in London on Sunday night.