Mile Jedinak's 15th-minute headed winner in Saturday's first leg at the Riverside Stadium handed the West Midlanders a slender advantage to take into the return leg at Villa Park on Tuesday.
Bruce, however, is not taking the first-leg result for granted, telling Sky Sports News: "We are pleased. Listen, all the cliches are going to come out, aren't they? Of course. We know the Championship is riddled with strange things. We have given ourselves a little advantage, a small advantage, but we're winning 1-0 at half time.
"I made that decision to try to get experienced players in the door so they could handle what Aston Villa throws at them. I thought it was vitally important that they can handle Aston Villa.
"That was the reason for going for the experience of [Glenn] Whelan, [Ahmed] Elmohamady, John Terry, of course, Mile - they all handle playing under pressure for a big club.
"When you're asking them to play in big semi-finals like tonight, then you need them to come to the party and, to a man, they did. I thought they were terrific."
Villa were relegated from the Premier League at the end of the 2015-16 season.