Both Ciaran Clark and Allan Saint-Maximin could miss the trip to Burnley this weekend after picking up muscle injuries in the 2-1 win over Southampton.
The Republic of Ireland international - who scored at Turf Moor last term - picked up a calf injury and came off at half-time against the Saints.
Although, Clark is in much better shape than Saint-Maximin after the French winger hobbled out of St James' Park admitting he'd suffered a "bad one" after sustaining a hamstring problem.
After the game Bruce said: "I toyed with changing us.
"It's the first time we've had three games in nine days and the extra day's recovery that Southampton had is huge.
"Because I didn't, we've probably picked up two muscle injuries which bear fruit of people not recovered.
"When people do it at half-time and full-time like they are, basically they are fatigued."
The good news for Bruce is that he has a healthy squad to bring in replacements.
Sean Longstaff and Andy Carroll came off the bench and played a big part.
While Atsu could be a simple choice to replace Saint-Maximin against the Clarets.
Bruce added: "I'm delighted to see Longy again.
"Look, the way to create the spirit when somebody comes into the team and does well is to reward them, and that's the way I've always tried to manage.
"I've had Fab Schar knocking on the door for weeks now he's back fit, but Dummett and Clark and Fede have been excellent.
"We've got Florian Lejeune as well, so we'll need them now.
"All of a sudden, we've got six or seven [I'm presuming he means injuries], so we need that big squad and that's when I'll use them all."
