But Bruce has ruled out selling the 28-year-old.
"Gayle has always been part of my plans," he said, despite Championship interest in Gayle. "I've tried to buy him twice but could never afford him.
"We've got a nice balance in attack.
"As well as the new players, I've been very impressed with Almiron and (Yoshinori) Muto so let's hope they can all score a few goals because a team is only as good as its strikers."