In his column for The Sun, Redknapp wrote: "He's not a punch-drunk heavyweight champion who's washed up, skint, comes back for another fight and gets knocked out. He has a swimming pool and a big house in California, with a lovely family and as much money as he could ever want.
"He could sit by that pool and have an occasional dip for the next two months - but instead he wants to keep on playing.
"But it's not the first time people have said I'm going off at the deep end in the transfer market.
"Paolo Di Canio, Teddy Sheringham, Stuart Pearce, Paul Merson and Kanu. I signed them all at the rusty end of their careers yet they turned out to be old but gold.
"With signing a big-name player like Beckham there are always going to be lots of details to sort out and the deal has to be right for everybody concerned. He feels he can still come here and play well and I still think he has something to offer as a player.
"It's going to be hard to shift Aaron Lennon out of the team, but he can give me something else.
"He can deliver that ball. It's no good having Peter Crouch if you can't get the ball to him in the air.
"I also think he would be a good influence on the other lads. You learn the game by being around good players and good pros and seeing how they behave."