Keane has been a hit at Celtic since joining the club on loan in the January transfer window.
Celtic boss Tony Mowbray has admitted that he would like to keep the Republic of Ireland striker at the club.
“I don’t see us loaning Robbie out again,” Redknapp said in the Scottish Sun.
“We paid a lot of money for him. So it’s not something I see happening. It would obviously be up to the chairman, but I couldn’t see it being a possibility.
“I certainly would not want it to be happening.
“Robbie’s only on loan until the end of this season as far as we’re concerned.
“We want him back so in my mind there’s no way of another loan deal.”
