Manchester United team-mates Paul Pogba and Romelu Lukaku were involved in a bust-up after their win over Southampton this weekend, UK Sun reports.
Lukaku netted a brace in the 3-2 victory but had the chance to complete his hat-trick late on.
But Pogba opted to take the penalty and saw his effort saved.
The victory was enough for United to leapfrog Arsenal to move back into fourth place, but it did allegedly spark a dressing room row between Lukaku and Pogba.
It is believed that Lukaku was disappointed that Pogba took the penalty against the Saints as he was on a hat-trick at the time.
The Belgian reportedly reminded Pogba that he supported him during the difficult Jose Mourinho period.
He also allegedly told him that had the roles been reversed, he would have let him take the penalty to complete his hat-trick.