Taarabt spent the first half of last season on loan at Fulham before taking in the second half of the campaign with AC Milan.
The Moroccan has been linked with a permanent move to Milan, but no deal has yet been agreed with the Serie A club.
The former Tottenham youngster was left out of QPR’s pre-season tour to Germany due to a lack of fitness, but Redknapp feels Taarabt can still be an asset for the club if he is in the right shape.
"The first day back training he wasn't fit and hasn't been fit to train since," Redknapp is quoted by Get West London.
"Then he said he was going to Milan last week. He hasn't gone so what we need to do with him is get him fit. He's got to train morning, noon and night really, whether he stays here or goes somewhere else.
"I've got a lot of time for Adel. He needs to get himself in shape, like the other lads have done. If he does that he will be a great asset to us I’m sure.
"He's got fantastic ability and a point to prove really in the Premier League.
"He went to Fulham last year and it didn't go for him. He went to Milan and did great. If he was here he would be a big asset to us. We need him fit and ready to play."