Townsend spent a spell on loan at QPR last term but any hope the Rangers boss had of bringing him back seemingly disappeared with the winger's fine performance in Spurs' 5-0 Europa League rout of Dinamo Tbilisi on Thursday, when he scored the opening goal.
Redknapp also admits he has little chance of raiding his former club for striker Defoe and left-back Assou-Ekotto as he plots a promotion push back to the Premier League at the first attempt.
The QPR boss told the Fulham Chronicle: "It was good to see him (Townsend) play so well, and I'm glad QPR played a part in his development, and that certainly pushed him on to where he is now.
"He had nine loans before that, and with us it was his first chance to show what he could do at the top level and it has done his confidence a world of good, but bringing him to QPR?
"No, definitely no."
As regards Defoe and Assou-Ekotto, he added: "Anyone would like Jermain, but it's a difficult one really. They're both Spurs players and it would be hard."