Former Manchester United captain Gary Neville says replacing David de Gea will be difficult.
De Gea is leaving United after 12 years with the club.
"I've said it's the single most difficult position in English football being the Manchester United goalkeeper," Neville said on the Overlap. I genuinely believe that. I think Liverpool's number one is the second.
"And that's not to be disrespectful to all other clubs, I think the Manchester United goalkeeper comes under more scrutiny if they make a mistake than any other position in English football on the pitch. It's tough and I've seen lads in that goal [struggle]. That's the problem they've got. It's whether [a new goalkeeper] can handle that stadium.
"I think it's that element of that lull that they experience where the team are attacking at home for, say, 10 minutes and the keeper hasn't touched the ball and they're just there. It's that concentration goalkeepers need to have when they're not involved in the game.
"I always think a Manchester United goalkeeper or any goalkeeper needs to have unbelievable concentration because you might go five minutes without touching the ball. We're [outfield players] always involved, or just in our positions, but a goalkeeper can just be redundant for a period in a game. I think that's a really tough thing to have to deal with."