The Tigers have been without Paul McShane since mid-February due to undergoing ankle surgery, and McGregor cracked three ribs and suffered a damaged kidney in the March 26 defeat at West Ham United.
With City due to take on Arsenal at Wembley three weeks today in the club’s first major final, the two men were expected to have no chance of being involved.
Bruce, however, has revealed that both McGregor and McShane returned to the training field this week.
He said: “Typical Allan, he is desperate to play some part. So I am not going to stop him.
“All he has done so far is have a jog around the training ground. That is a bit different to throwing yourself on the floor and diving around with three broken ribs.
“We will have to make sure he’s right. We will take no chances. I know how desperate he is to play but then again there’s 25 of them who are all desperate to play.
“It was a joke when I first said that he would be out for six weeks but the Cup final was in seven. Clearly, though, it wasn’t a joke to him. He is one of a rare breed. The kid is rock hard.
“The injury was pretty serious stuff. He was a hairline away from losing a kidney and that was only a month ago.
“Of course, we will protect him. We will also be governed by doctors and specialists. Same goes for Paul McShane. It is good to see him around after all this time. He’s on schedule.”
Asked if both had to play in the league to be considered for the Cup, Bruce replied: “To be honest, I haven’t even thought about that.”