Ahead of the crucial clash with City at Eastlands tomorrow night. Redknapp said that the chances of Tottenham pushing for fourth are now very slim as Bale requires surgery on damaged ankle ligaments he sustained against Blackpool yesterday.
“It will take a miracle (to finish fourth)," Redknapp said. "(City manager) Roberto Mancini has got a fantastic squad.
“They're in a great position. They are six points ahead of us and they have a better goal difference by miles."
Redknapp also said that the late-season form of his Spurs side had taken a dip as Bale and fellow star Rafael van der Vaart have dealt with injuries and individual form problems.
"When we've needed that little bit of magic in the last month or six weeks, Gareth has been injured and we've lost that little spark that turns draws into wins," the Spurs boss added.
"Gareth and Rafa were so good, they were the difference between drawing and losing. They were turning games with fantastic individual performances as well as the team playing well."