The Blues top scorer, who had already bagged his 17th goal of the season to give Blues a 3-1 lead handed the responsibility of taking the spot-kick over to midfielder Bryan Hughes who, had he taken it and scored, would have gone home with the match ball having bagged a hat-trick.
However, with Bruce shouting from the dug-out area, Forssell was told to take the penalty by the Blues boss.
"I was the penalty taker for the game and as a striker you want to get as many goals as possible," the Finland international said after the game.
"Steve Bruce was shouting from the bench for me to take it.
"I understand he (Hughes) wanted the hat-trick and I really feel for him. I thought he was the man-of-the-match today and I gave him the champagne at the end of the game because of how unfortunate it was for him."