Reports suggest he has just sprained his ankle but Redknapp says the club is unsure of just how serious the injury is and regardless, his absence will be cause for concern as Spurs are already without key midfielder Aaron Lennon, Jermaine Jenas and David Bentley.
"You're going to miss Tom - he's a top player for us," Redknapp said.
"He makes us play and he's a great passer and we needed that when we were going through that dodgy little spell. It was important we tried to get hold of the ball.
"We don't know how bad his injury is at the moment but it doesn't look good. He'll have a scan and we'll see how it is but we're running out of central midfield players - we've only got three anyway. It's not an ideal situation and it's an area we've been light on all season really."