Gary Neville has said Manchester United need a new defence 'in its entirety' after Tuesday night's Champions League humbling by Barcelona.
United were beaten 3-0 at the Nou Camp, with Philippe Coutinho's 61st-minute strike adding to Lionel Messi's first-half brace.
The loss is United's fifth in their last seven matches after the team had previously tasted defeat just once in Ole Gunnar Solskjaer's first 17 matches in charge.
The poor run of form serves as a reality check for Solskjaer and Neville believes that while some players will learn from the defeat, others simply aren't good enough to represent the club.
"There are big learnings tonight for some of those Manchester United players and for the coaching staff," Neville told beIN SPORTS. "For Marcus Rashford, he recognises what the elite level is in terms of club football, seeing Messi play there.
"You see McTominay in midfield, it's a big lesson for him over two games, he's done well in the games, but for some of the others they're not good enough and the coaching staff will see there is a massive gulf between Europe's best teams and where United are at."
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Neville didn't specifically name the United defenders he feels need replacing but he said the Reds' backline is in need of a complete overhaul.
"United need to revamp their squad, there is no doubt about that," Neville added. "He needs a new defence, in its entirety I would say."
On United's failure to mount a remarkable comeback against Barcelona akin to the one they mustered in Paris last month, Neville added: "This is where United are at, Paris was a freak.
"I said before the game [against PSG] that I didn't think United had a chance, it was a one in 50 and it happened.
"This was a reality check, the last few weeks have been a reality check for Manchester United but tonight makes you feel about how far they are from being the team that they need to be."
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