Despite his decent form, Malbranque has been substituted in nearly every game this season. The Sunderland manager has dismissed any concerns about his fitness, saying the winger plays the game at an intensive level.
Bruce said: "I think he fatigues himself that quickly because he does a lot of intensive running. He's not one of these who just saves himself for the end. I think it's mainly mindset more than anything.
"He ran himself to a standstill at Old Trafford. I think he had cramp in both legs. If you can do it at Old Trafford (last for 90 minutes), you can do it anywhere.
"I thought he set the tone for us at Old Trafford. He took the ball and kept it, and showed a lot of courage with the ball. I thought his performance was magnificent."