Wayne Rooney insisted his bold 'risk and reward' policy will continue despite his Derby side giving the ball away for both goals in their 2-0 defeat away to Birmingham.

Sloppy passes from Derby enabled Scott Hogan to score the first home goal at St. Andrew's this season in the 31st minute before Jeremie Bela wrapped up the three points nine minutes from time to send Lee Bowyer's outfit fourth in the Sky Bet Championship.

"The way we're trying to play, there are going to be mistakes. I've told the players that and I take full responsibility for that," said Rooney.

"I'm asking players to play out from the back and every now and again it doesn't come off – that's on me.

"So I'm not going to criticise the players for giving the ball away by playing the way I want them to play.

"On the other hand, we do need to recognise moments when we can play the ball in behind as well – that's why I made the change at half-time (Jack Stretton on for Graeme Shinnie) because I didn't feel we were playing the ball into the channels with balls into space.

"It's about recognising those moments when you can play forward and play it in behind."

Birmingham head coach Lee Bowyer, meanwhile, has called for protection for Tahith Chong after the on-loan Manchester United winger was caught by some uncompromising challenges.

"Did you see some of the challenges on him?" said Bowyer. "It's not his fault he's good, you can't just allow him to get kicked and fouled the way he was.

"He went past one player and someone took him out knee height – he didn't play the ball because Tahith just went past him too easily, but they have to protect him.

"He got an arm in the face. Was it on purpose? I don't know.

"But you can't just allow someone whenever he lays the ball off, there were late tackles on him.

"They have to deal with him better. I know it's a non-contact sport now but even in my day some of those challenges were bad."

Troy Deeney made his Birmingham debut when he came off the bench as a 68th-minute substitute for Lukas Jutkiewicz.

"I know what I'm going to get from Troy," said Bowyer. "To pick up the crowd at a time when we needed them, he did exactly that.

"He held up the ball, caused them problems, and he will improve. He has made us stronger as a group.

"Troy made the impact we were looking for."