Lennon suffered an injury setback last month, having already been sidelined for two months, after suffering more tears in his troublesome groin muscles.
Wing man: Aaron Lennon was 'absolutely flying' before his injury
And Redknapp revealed he could not be sure that Lennon, 22, would play again this season, placing his chances of boarding the plane to South Africa in jeopardy.
'We have lost Aaron Lennon for God knows how long and he was absolutely flying,' said Redknapp, whose team face Blackburn.
'He has not started outside work again, not running or anything so we're going to wait and see with him. I couldn't sit here and say for sure (he will play again this season). I hope he's going to be fit.'
With the likes of Theo Walcott, Shaun Wright- Phillips, James Milner and David Beckham all vying with Lennon for the England right-wing berth, the Spurs star will be desperately hoping he can get some game time under his belt before Fabio Capello names his provisional 30- man World Cup squad on May 30.
There was better news on Ledley King's return from a thigh injury, with the defender expected to return within a fortnight.
And Redknapp still has a sneaking suspicion King (right) will be included in Capello's plans.
But Tottenham fans will not see Jonathan Woodgate in action again this season after he had surgery in Australia yesterday in the hope of curing his groin problem.
Redknapp added: 'There were a couple of options and they feel they've got the right answer so we'll have to wait and see. He'll spend the next few weeks recovering in Australia.'
Jermaine Jenas is on the road to recovery after a successful hernia operation, but Redknapp could be left short in central midfield with the combative Wilson Palacios a yellow card away from a two-match ban.
Redknapp has set his players the target of 19 points from their remaining 10 games if Tottenham are to stand a chance of Champions League football next season by finishing fourth.
'We are going to have win six games I would think and get a draw somewhere out of some very tough games.
'We have got Chelsea, Manchester United and Arsenal and are away to Stoke and Sunderland. It is a big ask and we have got a really tough run-in,' he said.