Goals from Kevin Schade and Yoane Wissa inflicted a damaging defeat, which leaves Forest sixth.

Morgan Gibbs-White scored the only goal of the game.

The Arsenal boss said the clash shows the players are “demanding excellence”

The England forward, banned since May, was on target in his return as Brentford beat Nottingham Forest.

The Red Devils are under intense scrutiny given they are already out of Europe, the Carabao Cup and Premier League title race.

The Portuguese has returned to English football after two years away following Cooper’s sacking on Tuesday.