Townsend suffered a hamstring problem in training during the week, and Redknapp has ruled the 21-year-old out of the club's match with Reading on Sunday.
The former Spurs boss told reporters: "Andros picked up a bit of a hamstring. He's gone back to Tottenham for treatment.
"We hope he'll be available for the Arsenal game. There's every chance he'll be available for that game. He's gone back for treatment – that's normal."
The England Under-21 international has scored twice in eight games for QPR since his arrival in January.