Gary Rowett was impressed with the performance of Murray Wallace in an unfamiliar midfield role as he scored twice in a 3-1 Carabao Cup win over Cambridge.
Boss Rowett made seven changed after back-to-back defeats in the Sky Bet Championship, including pushing defender Wallace into midfield, and it paid dividends as his brace before half-time turned the tie on its head.
Rowett said: "I think you saw a different side to Muzza (Murray Wallace) that I don't think I've ever seen before and I didn't think he would be inches away from a hat-trick. I thought he was really, really good.
"I felt it was the right game to give players an opportunity to see what they can do and the players that came in, I thought they did really well.
"These cup ties can be a bit testy sometimes and I'm sure they would have looked at our last two results and thought we might not be as confident as we would have liked to be."
George Williams had opened the scoring for Cambridge just after the half-hour, before Wallace's quick-fire efforts.
Matt Smith then sealed victory eight minutes after the interval, but Cambridge boss Mark Bonner was proud of his team's efforts.
He said: "I thought for the first 35 minutes we were brilliant and I thought we looked like we were getting on top second half but they broke on us a couple of times. We did have control for spells.
"I love the endeavour of the team to keep scrapping out.
"We had some good chances and went toe-to-toe with them and for a team that changed quite a bit tonight and a team that's trying to find its feet in League One, we were really competitive against a Championship side, and a good one."
