Former Manchester United striker, Michael Owen, has delivered scathing criticism, calling for manager Erik ten Hags dismissal.
Manchester United faced their worst defeat this season at Selhurst Park, with Michael Olise shining for Palace.
Jean-Philippe Mateta and Tyrick Mitchell added to Uniteds woes, as Ten Hags side faltered.
The loss leaves United languishing in eighth place, facing their lowest-ever Premier League finish.
Owen insists that Sir Jim Ratcliffe and INEOS must bring in a new manager before next season.
He emphasizes Ten Hags unsuitability for the job, stressing the need for a managerial change.
Speaking on Premier League Production, Owen predicts a dire future under Ten Hag, foreseeing heavy defeats against Manchester City and Arsenal.
"I have said it for a long time that Ten Hag is not the right man for this job, I have been saying it for ages and ages," Owen said.
"He cannot, simply cannot, manage the team next season.
"I almost wonder now, they've got a cup final and they've got a few important games that could mean European football next year or not.
"At some point you've got to make a decision, they are going to get absolutely hammered by Manchester City [in the FA Cup final], they're going to get annihilated, in fact, Arsenal will smash them to bits at Old Trafford."
EPL: He's not right manager - Michael Owen begs Man Utd to sack Ten Hag
