Arsenal teammates Declan Rice and Gabriel Magalhaes turned on eachother during defeat at Fulham.
The Gunners struggled throughout the 2-1 reverse on Sunday.
Gabriel and Rice were seen in an angry exchange just moments before Bobby Decordova-Reid struck the winner for the Cottagers.
Defeat saw Arsenal miss the chance of finishing 2023 top of the Premier League table.
Being brutally honest, it's not good enough," Declan said after the game. "The standards that we've set over the course of the season so far have not been met in the last two games."