The 31-year-old striker joined the west London outfit upon Blackpool's relegation from the Premier League in 2011, but failed to impress then-manager Mark Hughes.
The former Leicester City forward was subsequently loaned out to Portman Road, where he has scored eight goals in 12 appearances in the Championship.
|WE R BOTTOM
|2/1||QPR are 2/1 to finish bottom of the Premier League with Bet365|
"I wish he was here now," Redknapp told TalkSPORT.
"He would be more than useful. He gives everything and has done very well at Ipswich. I wish he was around for us at the moment.
"We need all the bodies we can get. If he comes back I am sure he will do well."Bottom-of-the-table QPR host Fulham on Saturday and are still looking for their first league win of the season.