Just 24 hours after attracting interest from Lille, Utaka has been warned by Redknapp he must produce more to win a place in his first team.
He said: "I need a bit of pace in the team, it's something we're short of. John Utaka could give us a bit of pace and wide options for sure, he can run quick. He's got to use that pace, though, that's the key.
"He's got to get the ball, work hard, try to use his pace at the right times and take people on at the right times. That hasn't happened yet. John's got to put all these together. He's got to put his game together a little bit more.
"It will be a big year for him, it's got to be. He did okay last season but I am expecting better from him. In fairness, it takes a year to settle in for lots of foreign players. It's a different game and we are asking them to do different things.
"We've been asking John to play 4-4-2 and tracking back - he would not have done that before in his life in France. It's a case of you need to work on people on the training ground and hopefully it sinks in.
"He's had some great times, though. He got goals against Bolton, Newcastle, Reading and Derby last season. He's capable of getting 10-12 goals a year really. We just need more from him."