He caused havoc with his darting runs infield from the left flank and could have had a goal himself before Darren Bent scored the winning goal from the penalty spot.
"Danny's something a bit different and when he came on he looked to take us forward," Bruce told safc.com.
"He always got at City if he possibly could and that's why we brought him in, for times like that, because of his quality.
"We all know he's got that; he needs regular games to get experience under his belt."
And Bruce thinks Welbeck's two-goal show for England's under-21 side in Colchester is another positive step forward.
"It was great to see Danny scoring twice - it just shows he's always a threat," Bruce added.