A member of the Manchester United coaching staff could find himself in trouble with the FA following a furious rant at officials.
De Ligt had been ordered to come off the pitch by referee Samuel Barrott to attend to a head wound that wouldn't stop bleeding.
United won the game 2-1, with Alejandro Garnacho and Rasmus Hojlund scoring in the second half, but they were still livid with the incident regarding de Ligt.
A member of the Manchester United coaching staff could find himself in trouble with the FA
As reported by The Mirror, United coach Darren Fletcher could be punished after he was seen raging at fourth official Gavin Ward along with Barrott as they walked into the tunnel at half time.
United manager Erik ten Hag and assistant Ruud van Nistelrooy had both received yellow cards for their protests.
De Ligt himself was seen abandoning his treatment and kicking a ball away in fury. He had required treatment after colliding with the knee of Brentford's Kevin Schade.
Fletcher must now wait to see if Barrott will include the incident in his match report.
A product of United's academy, Fletcher made 342 senior appearances for the club and scored 24 goals, while he won an array of trophies.
Fletcher's 17-year-old son Jack was named on the bench for United against Bournemouth.