Speaking to Sky Sports, O'Hara said: "Shocking. I thought they were terrible. They were so bad. It is actually probably the worst Manchester United final performance I've ever seen. They were absolutely awful.
"The manager inept of ideas, didn't know how to change it, didn't know how to affect the game. Made substitutions too late. He should walk because he ain't the right man for the job. He's really not the right man for the job. And the performances he's put in since he's gone there have been shocking. He should walk but no one walks anymore because there's too much money on offer. So he's not going to walk.
"Who's going to join United? They're 16th in the table. They've got no European football and everyone knows that the club is cost-cutting the wages. They're getting rid of everyone. With Jim Ratcliffe, it's like a fire sale. Everyone's up for sale. Who actually is going to want to join United?"