The World Cup winner has been linked with a number of clubs during the off-season, with Arsenal, Barcelona and Manchester City all credited with an interest.
In recent days Valencia have insisted that they will not be welcoming any bids for the player, but Redknapp is keen to bring the player to White Hart Lane.
"The chairman has been dealing with it," confirmed Redknapp after Spurs' friendly victory at Brighton & Hove Albion yesterday.
"[Mata] is a player we like, obviously, so do Arsenal, so do a few other clubs, but where it's all at I don't know.
"He's a player I went and saw when England played Spain Under-21s and I thought he looked fantastic.
"Whether anything happens I wouldn't be sure, the chairman is the only person who has been dealing with those transfers."
The 23-year-old began his career with the Real Madrid academy.