Lennon, who is aiming to be selected in England's World Cup squad, will now have to rest his injury until April.
"We are picking up a few knocks to key players," said Redknapp.
Tottenham are keen for Lennon to be fit again - in their quest for the final Champions' League spot, crucial players have suffered injuries.
David Bentley has also picked up a groin injury, Jermaine Jenas undergoes surgery this week and Tom Huddlestone is the most recent victim, picking up a leg injury in the match against Everton.
"Aaron has had a scan, and has just torn a couple fibres away apparently," Redknapp said last week.
"It is difficult and has been dragging on a long time. We will just have to wait and see.
"Another little setback is not what he wanted, but he will get on with it. When he does come back, he will be as good as ever.
"So long as he gets back and gets enough match action for Tottenham to take us where we want to go, then the World Cup will follow.
"But, first and foremost, we have to get him back playing for Tottenham."
He's the only player that really gets me excited about watching my beloved Spurs these days.
Before his injury, Lennon had edged ahead of rivals Theo Walcott, David Beckham and Shaun Wright-Phillips in the England pecking order, playing in the last three World Cup qualifiers, and he was also a key part of Tottenham's push to earn a Champions League place.
England coach Fabio Capello will have to do without Lennon for the squad that will face Egypt on Wednesday 3 March.
However, he will hope Lennon manages to play regularly before the World Cup in South Africa this summer, with England's first game being against the United States on 12 June.
Source: BBC Sport
Source: BBC Sport