Newcastle United have been rocked by a major blow going into the weekend clash at Burnley with Jamaal Lascelles ruled out at Turf Moor.
The Toon skipper now faces scans on a stress fracture to his foot and could be missing beyond Sunday's game.
Both Federico Fernandez or Ciaran Clark are in line to step in and replace Lascelles.
Bruce said: "The disappointing news is Jamaal Lascelles is missing with a foot injury suffered last week.
"It's not looking so good at the moment so he will have more scans over the weekend, he won't play this weekend that's for sure, it's a stress fracture."
Bruce was cautious about the chances of Callum Wilson and Allan Saint-Maximin but said: "We still have two sessions to go
"Callum and Allan have trained all week.
"They are available.
"It has been great to see them back on the training ground.
"Even the top teams without their best players it's a struggle.
"We have missed our top players."
However, Bruce does not feel that Ryan Fraser will be ready after he picked up a calf injury.
But there was better news on Andy Carroll who will train today after a muscle problem.
