Sir Alex Ferguson has questioned whether David Beckham's short-term loan move will be of significant benefit to Tottenham.
LA Galaxy midfielder Beckham, 35, is due to seal a two-month loan to White Hart Lane on Sunday as he seeks to convince Fabio Capello that he still has a future at international level.
Harry Redknapp believes Beckham's experience and character will be a real boost to the squad as they look to play their part in the title race, but Ferguson is not convinced.
"The thing with David if he comes to England is that he will have to go back in March," Ferguson said. "It's a very short-term loan and we had the same situation with Henrik Larsson in 2007.
"We utilised those two months well and Henrik played a great part, but we knew we would miss him at the very time when we would have liked to have had him - at the tail-end of the season - but that was the arrangement, so we had to move on."
He added: "Obviously anyone at 35 is looking at the twilight years of his career. I have players at United like Paul Scholes, Ryan Giggs and Gary Neville who grew up with David and are at the same level.
"They know they are coming towards the end of their careers and the horrible part of being a manager is seeing that. These players are eventually going to retire. David knows that better than anyone."
Redknapp, though, feels the signing will give the fans a lift and expects Beckham to prove his worth during his brief stint.
"They [the fans] will be pleased to have him here," Redknapp said. "Everyone respects him. He wants to play football.
"Most players would sit around thinking, "That's okay, I've got eight weeks now to sit around the pool. Go and have a game of golf, or whatever" but he wants to play.
"It tells you everything about him. That's why he's probably had such a great career. He's always worked hard. He always puts a shift in. He's a good trainer. You never hear anybody who ever played with him criticising him."
Redknapp also reiterated that he has no plans to sign Ajax striker Luis Suarez.
"He's a good player but we haven't made any offer for him," he said. "I would doubt very much that anything will happen there. I've watched him loads of times; he's not an out-and-out striker but he could play anywhere."