Rooney was widely criticised for his showing on Friday, with Fabio Capello admitting the striker "lost a lot of balls and a lot of passes" and suggesting he was struggling with the pressure.
Redknapp said in the Sun: "If I'd asked you to go and watch Rooney on Friday, say he was available and I could get him for £1.5 million, you would have come back and said: 'Nah, you can't take him - he's not good enough'. If you didn't know it was Wayne Rooney, you would have thought he was a poor player."
Redknapp also believes Capello is failing to get the best out of Steven Gerrard. The captain put in an impressive showing in the opening game against USA from a central position, but he was disappointing when played on the left against Algeria.
"You have to play people in their best positions," Redknapp said. "Gerrard is a central midfield player. Play him off of Rooney, get him in the middle. The one thing you wouldn't want to do is play him wide left. The balance is wrong."