The veteran striker is available as he comes off contract with Atletico Madrid.
Gallardo said: “I spoke with him, I know him, I have a good relationship with him. I respect the player and the person. I contacted him to find out what was going to happen in his life and if he wanted to come and play in Argentina, in an institution like ours.
"It is difficult to talk about a possibility that it is not known if it can be real beyond the interest of the club and beyond the fact that the footballer has valued it and takes it into consideration.
"We have to wait and see what the real possibilities are."