Former Manchester United legend Roy Keane believes the Red Devils must bring at least six quality players to the club during the summer to stem their steep decline.
The Republic of Ireland assistant boss was speaking after David Moyes' men slumped to an embarrassing 2-0 defeat away at Olympiakos.
"Even forgetting about tonight's result and poor performance, I feel United need six players, quality players," Keane told ITV.
"Vidic is leaving in the summer, rio is coming towards the end, speculation over Evra, Giggsy you would expect to retire.
"So I think five or six players to try and rebuild the club."
The Cork man felt the Old Trafford side were carrying a few players on the night and they were dominated by the Greek Champions.
"It's been a long night and a tough night for the supporters no doubt and David Moyes and his staff. I don't think anyone could have predicted that was coming," he added
"Before the game we looked at Olympiakos and we weren't that sure about them, fancied United all day and they just never turned up.
"Criticise United all you want but let's also give a bit of credit to Olympiakos they were very, very good, on the front foot and technically they were better than United.
"United missed out in some players in the last few years. there were certainly one or two players playing for United tonight who just haven't shown enough quality."
Keane believes that the results for the English clubs over the past few days prove that the Premier League is losing ground on the top teams from other European leagues.
"I think we've also been brainwashed by this Premier League that it's the best league in the world... Nonsense'," he said.
"I think it's the best brand but we've seen over the last few weeks with the Englishteams struggling that these teams have fallen behind the best teams in Europe, United particularly."