The 30-year-old striker signed a new contract at the club in the summer after his deal expired – but he’s yet to play a minute of Premier League football this season, despite the loss of Callum Wilson to injury.
Gayle – who was reportedly involved in a training ground confrontation with Graeme Jones, Bruce’s assistant, this week – was an unused substitute for last night’s 1-1 draw against Leeds United at St James’s Park.
Asked why Gayle hadn’t played, head coach Bruce said: "I think it's the system that we’re playing, which I’m looking at, of course.
"Dwight trains every day, he’s a great pro. He’ll be frustrated, I’m sure. Well I know, for a fact, he is, but, then again, so are 10, 12 other players. I’ve got to pick a team to win a football match, and go with a system, and he hasn’t found a way in yet.”