The 21-year-old has found opportunities hard to come by at United since joining the club last summer from Crystal Palace, and rumours have been linking him with a move away from Old Trafford for the majority of the summer transfer window.
Last week it was reported that the England international was very close to a move to QPR, but little has emerged since that rumour was first reported but The Sun.
Redknapp, known for his late dealing in transfer windows, has now admitted in his weeky press conference that Zaha is a player that they, plus a number of other clubs would in interested in if he became available.
He said: "If they were to loan him, I don't know if they would. He belongs to Man United, it's up to Man United if they loan him out or not, but if he did become available on loan he's a player that I'm sure a lot of clubs would be interested in."
When asked if the Hoops had enquired about the services of the £10 million man, Redknapp responded: "Not really, not at the moment. But if we thought he was available he would certainly be of interest."
Despite impressing in pre-season training under David Moyes last year, Zaha wasn't really given a chance in the United first team and spent the first half of the season in the reserve squad.
He was shipped out on loan to Ole Gunnar Solskaer's Cardiff City in January but failed to make a significant impact in Wales making 11 appearances and scoring no goals.
Zaha did play a role in Louis van Gaal's first pre-season as United manager in the USA, playing as a striker.
However with the competition for striking positions at United very tight, and Van Gaal's system of wing-back, it's thought that the Dutch manager would be open to the former-Palace man leaving on loan.
It was also reported that Crystal Palace would be very interested in seeing their ex-star player return, but a move now seems unlikely with the Eagles being managerless at present.