Spurs secured a hard fought 1-1 draw against Blackpool but were hit by the withdrawal of Bale in the 62nd minute. The Wales international went down clutching his left ankle after being sandwiched by Keith Southern and Charlie Adam, before subsequently being stretchered off.
"He has done his ankle, it looks quite bad," he said. "We are not sure whether he has done his ligament or something. They are checking up on him but it is quite swollen."
The injury looked serious and Bale was seen leaving White Hart Lane with a protective boot on his left ankle. The club have said Bale will have the injury scanned on Monday and Redknapp is hoping for the best.
He added: "It looked a bad challenge, to be fair. But that is how it goes.
"They will scan him for sure and see how it is. It might not be so bad. He might have done his ligament, it may just be a twist. I don't know, we'll have to wait and see."
After Bale was replaced, Jermain Defoe grabbed a last-gasp equaliser to keep Tottenham's fading Champions League dreams alive. Charlie Adam looked to have netted a winner for Blackpool after scoring from the penalty spot at the second attempt.
Heurelho Gomes saved Adam's first shot but then gave away a penalty in the resulting play that the Scotland international finished clinically. Gomes' mistake came just a week after his gaffe in the 2-1 defeat at Chelsea but Redknapp insists he still has confidence in the Brazil international.
"He made a great save from the penalty and a great save just before that when they had an opportunity," he said. "I think everybody sort of lost their cool. We saved the penalty and instead of calming the situation down and dealing with it, we were all jumping around slapping one another on the back.
"The ball comes in and we don't deal with it."
Source: PA
Source: PA