Moise Kean
The former Premier League star returned to the field after a blow to the head.
The ex-Everton and Juventus forward has moved for a reported €13m transfer fee.
Juventus suffered a 1-0 defeat to AS Roma on Sunday, with substitute Kean being sent off just 40 seconds after coming on.
Allegri has had to deal with a lot this season but he's clearly still willing to back his players, after confronting a fan in the stands.