Former Manchester United defender Jaap Stam admits his old club took an unnecessary risk by appointing Ruben Amorim and switching to a back-three in mid-season.
Amorim played an untried combination of Noussair Mazraoui, Victor Lindelof and Leny Yoro as United lost 4-1 at Newcastle on Sunday, suffering a club record equalling 14th Premier League defeat of the season.
Stam, who won the Champions League and three Premier League titles under Sir Alex Ferguson, believes United should have chosen a head coach who was a better fit for the squad left behind by Erik ten Hag when he was sacked in late October.