Tottenham will definitely be without Aaron Lennon for Thursday's encounter with Chelsea, while Gareth Bale is also a doubt for the match at White Hart Lane.
Lennon managed only 26 minutes during the 1-0 victory against Sunderland on Sunday before he was forced off with a hamstring tear.
The 24-year-old is expected to be unavailable for a number of weeks, which serves as a significant blow to Spurs' hopes of domestic glory.
Bale, meanwhile, did not feature against Sunderland, having sustained an ankle knock in training in the days running up to the weekend contest.
The Welsh winger is now in a race to be fit in time to face Chelsea, while Jermain Defoe is still not a certainty for this week's London derby.
"Bale has sprained his ankle," said Redknapp. "He just did it in training.
"He thought it was okay, then he went home, had a little rest and couldn't put any weight on it.
"Lennon has got no chance for Thursday. It'll be weeks if it's a tear.
"There's every chance Defoe will be fit. He's only got a grade one tear and he's desperate to play, the little fella'."