Van der Vaart limped out of Spurs' 2-0 defeat at Manchester United on Saturday clutching his hamstring and was expected to miss Tuesday night's clash with Inter at White Hart Lane.
The Dutch midfielder has scored five goals in nine games since his £8 million signing from Real Madrid and it would be a huge bonus if he can win his fitness battle to feature against Rafa Benitez's Group A leaders, who beat Spurs 4-3 at San Siro.
Tottenham will be without injured first-choice defensive pairing Michael Dawson and Ledley King, as well as Jermain Defoe. Goalkeeper Heurelho Gomes will also miss the match through suspension after his red card in Italy a fortnight ago.
Prior to Monday's training session, Redknapp said: "The problem is I've probably got five of our very best players missing. The goalkeeper is out, he is suspended, my two centre-halves are out, and there is also Van der Vaart and Defoe. They are key players right down the middle of the team, so it's going to be very difficult.
"Van der Vaart is quality, but I think he just got a bit tired and that's when you get injuries. He hasn't really had many 90 minutes under his belt. At the World Cup [for Netherlands], he wasn't playing 90 minutes and when you get to that last 25 minutes and go a bit further than you normally go, that's when something can go wrong."
Midfielder Tom Huddlestone also shook off an injury to train at Spurs Lodge in Essex on Monday.