Grealish, 22, made his first start of the campaign in the 2-0 defeat to Derby County having missed the opening three months of the season with a kidney problem.
He was drafted into the team after Keinan Davis reported ill overnight and impressed Bruce with his display against the Rams.
“We know what he’s capable of and he’s had a good impact off the bench in previous games,” Bruce said.
“He’s played very well today.
“We’ve got to find him a position in this team that suits him while keeping the balance too.”
Derby capitalised on a Glenn Whelan error to open the scoring through Andreas Weimann before Johnny Russell secured the points late on.
Bruce said: “There wasn’t a lot in it really, aside of the fact we’ve gifted them the first goal.
“We chased it from there on and Robert Snodgrass in particular came close, having a shot cleared off the line.
“If that goes in, then who knows, but overall it’s disappointing because we’ve gifted it to them.”
Villa host fellow play-off contenders Sheffield United next Saturday – the first of four games in nine days – and Bruce is eager to return to winning ways.
“The Christmas period is upon us and we need to bounce back,” he said.
“We need to show that resilience again.
“It’s our first defeat in six games and we have to dust ourselves down and come back better.”