Erik ten Hag has been told "not to give Bruno Fernandes the captain's armband again" after his antics during Manchester United's 7-0 collapse at Liverpool.
United have been the Premier League's in-form team since the World Cup and last weekend ended a six-year trophy drought by beating Newcastle 2-0 in the Carabao Cup final at Wembley.
The progress made under manager Erik ten Hag came to a shuddering halt on Sunday though, as United suffered a second-half collapse against their fiercest rivals.
The first half had been a fairly even contest, with only Cody Gakpo's superb opener separating the sides. The floodgates opened after half-time though as Mohamed Salah and Darwin Nunez both scored braces, Gakpo grabbed his second and Roberto Firmino completed the rout.
After the match, pundits and former players queued up to pick apart United's spineless performance, and there was one topic in particular they kept coming back to.
With club captain Harry Maguire starting on the bench, Bruno Fernandes wore the captain's armband. The Portuguese international cut a frustrated figure for much of the afternoon, and now stands accused of diving, asking to be substituted and pushing the linesman.
Former Premier League striker Chris Sutton - often critical of the prima donna behaviour of footballers - was not impressed.
"The Incredible Sulk racked up quite the rap sheet at Anfield," he wrote in the Daily Mail.
There was nothing professional about this behaviour. It was more befitting a petulant child, and the push on the assistant should result in a ban, no ifs and buts.
"Paolo Di Canio got 11 games [ban] in 1998, remember, and I wouldn’t disagree if Fernandes received the same punishment. This was shameful, embarrassing, disgraceful, whatever word you can conjure up.
"Whatever you think of Harry Maguire, the club captain, you would not catch him behaving like this on the pitch. Ten Hag dealt with the Cristiano Ronaldo problem.
"Now he needs to deal with Fernandes, starting with deciding whether he deserves to wear the armband in Thursday’s Europa League clash with Real Betis. I don’t think he does. Liverpool were fantastic and United were foul, and nobody embodied their deplorable display more than Fernandes."
United's players reported to training at 9am on Monday morning, with the Manchester Evening News reporting that Ten Hag arrived at Carrington two hours before that.
They'll have to dust themselves down and prepare for Thursday's visit of Real Betis in the Europa League last-16.