Defoe is rated as 50-50 for the clash at Craven Cottage, with Ledley King already ruled out with a thigh injury and groin problems accounting for Aaron Lennon, David Bentley and Jermaine Jenas, while Tom Huddlestone has damaged ankle ligaments.
“Jermain has had tight hamstrings, run down his legs like sciatica-type pain,” Redknapp said. “He felt it after the game at Wembley, he didn’t feel very good with it at all.
“He felt his back was tight before the game and he’d been having treatment on the back of his hamstrings here, but they all seem to roll into one. The physios will see if they can work their magic on him.”
Redknapp added: “It’s quite easy to pick the team at the moment because I think we’ve got about 12 fit players,” Redknapp said.
“We’ll have to play people out of position but we’ve still got 11 very good players.”
Jenas underwent an operation in Germany this week, while Huddlestone’s foot is in a protective boot and he needs another scan before it is known how long he will be out.
Lennon’s injury is also worrying as he has not played since December and a comeback date has not been set, with the winger given the instructions to rest for six weeks.
Redknapp is expecting a tough test against Fulham, adding: “To beat Shakhtar Donetsk over two legs was one of the great performances because they’re UEFA Cup holders.
“Fulham are a well-drilled, organised team. Roy gets everything out of them. People like Danny Murphy, Roy’s resurrected their careers almost. It’ll be a very difficult game.”
Hodgson, meanwhile, has challenged his Fulham players to seize the moment and book their trip to Wembley.
Victory over Spurs would secure a first visit to Wembley since 1975 when they lost to West Ham in the final of the same competition and continue a season in which they continue to defy all expectations.
“It would be great on a personal note to lead a team out in the semi-final at Wembley,” said the Fulham manager.
“But more importantly it would be great for the club. These are the type of goals you set yourself. When you get this close you realise you’ll never have a better opportunity.
“Our players know this is a great opportunity. We worked hard for it, it’s been handed to us and now we need to do what’s necessary to bring home the bacon. Our moment has now come,” he added.