The current Hull City boss was offered the job while at Birmingham City, but says that he rejected it because he had just committed himself to the Blues, something that he now regrets.
"I could have done, and in hindsight it was a mistake I didn't go there," Bruce told Sky Sports News.
However, Bruce says that he was guided by his loyalty to Birmingham.
"It was just the timing of it, I'd committed myself to Birmingham at the time and there was this stigma about loyalty with me at the time. I only had four clubs as a player, I seemed to have four clubs in 20 months when I was a manager," he added.
"I always think what if. But as I said I'd committed myself to Birmingham at the time and it didn't happen so I had to see it through and there you go."
Bruce has managed Sheffield United, Huddersfield Town, Wigan Athletic (twice), Crystal Palace, Birmingham City, Sunderland and Hull.