The Frenchman limped off after just 16 minutes of his full Magpies debut at the Tottenham Hotspur Stadium on Sunday with a hamstring problem.
An intitial report suggests the severity of the issue is not as great as initially thought, but the club will know more about their £16million man later today.
“Allan trained all week, we thought he was OK. The first time he exerted himself unfortunately he pulled up,” said Bruce ahead of tomorrow’s League Cup clash against Leicester City.
“We will let the bleed settle on his hamstring. The initial scan think it is not that serious but we will not know the severity of it later today.
“The one thing you, and for him too, we didn’t look at him as a risk.”
The speed at which the winger was forced off has led to some criticism of Bruce playing him.
But the head coach has defended that decision.
“He trained all week. He was available for every session. Disappointing,” he said.
“It has been a frustrating start for him. Hopefully we get appositive scan for him.
“The international break comes at a big time for him. If not too serious we would be looking at three weeks so that would be good news. For him the int break is a good time, we have a few knocks and bruises.”