The 23-year-old is set to quit the Spanish La Liga side this summer and has been heavily linked with a move to Arsenal as Arsene Wenger considers a replacement for unsettled star Cesc Fabregas.
But Tottenham are also keen on signing him and revealed that chairman Daniel Levy is involved in talks about bringing him to White Hart Lane.
Redknapp said: "(Mata) is a player that we like. So do Arsenal and so do other clubs. I went to watch him when England Under-21 played Spain and I thought he looked fantastic.
"The chairman has been dealing with it so where it is I don't know - I don't deal with them transfers.
"I wouldn't want to say that it isn't happening in case we sign him tomorrow and you all say 'thanks Harry', but he's a player we like."
Should a move for Mata materialise, it would further fuel speculation over the future of Luka Modric, who is attracting interest from a host of clubs including Chelsea.