The former Sheffield United defender has not featured since that difficult start, spending most matchdays as a non-playing substitute.
Bruce claims he has not written Kilgallon off, though.
"It was a bit unfair on him," he told the Sunday Sun. "He came in the middle of a tough run.
"A bit like Paulo da Silva, we took him out of the firing line and we can bring him back when the team's a bit more confident.
"Matthew Kilgallon will have a big part to play, I'm convinced of that. He's got all the natural attributes. But the time he came in the team was doing poorly. I just wanted to protect him as a new signing rather than throw him in at the deep end.
"Part of it was the fact he'd been out of the Premier League so long, and letting him get established with the players and get a feel for what we want. I'm sure when he gets his chance again, he'll do very well."