The 19-year-old has impressed for the Black Cats int he Premier League this season, but was forced off with an ankle injury against Wigan at the weekend.
“It looks a nasty one for the kid. His youthful exuberance has been a massive help to us and he will be a big loss,” said Bruce.
“He’s definitely going to be out for weeks and maybe even months – but we have to move on and manage without him.”
“He’ll have a scan on Thursday once the swelling has gone down, so we won’t know any of the serious stuff until at least then,” he revealed.
“If it’s a normal twisted ankle, then it looks like he’ll be out for four to six weeks.
“It seems to be our season so far where people who have been playing very, very well for us get injured or suspended.
“That’s been the problem over the last couple of months. The kid’s done fantastic and he’ll be a very big loss for us.”
