Townsend has been excellent for QPR in recent games.
Redknapp said: "Townsend has been excellent. He's done great for me, so it was a difficult one leaving him out.
"He's been as good a player as we have, but I decided to give Junior Hoilett a run today.
"I felt we needed a target, so I brought [Jay] Bothroyd in as Bobby [Zamora] wasn't fit.
"Adel hasn't been at his best so I left him out."