Both players were substituted in the first half of the televised Sky Bet Championship clash, with Kane suffering a hamstring problem before Elder picked up a concussion after being elbowed by Paddy McNair.
Speaking after last night’s game, McCann said: “Herbie looks like a hamstring injury. That was disappointing. It doesn’t look too severe so hopefully we have caught it early but we won’t know the extent until I’ve seen the doctors and the physios.
“It didn’t look too pretty for Callum. He had to come off with a concussion. I think it was a little bit of a sly elbow but we couldn’t take any risks with him.
“I don’t think he was answering the questions the doctor wanted to know, so we had to take him off. So again, we’ll probably have to follow a protocol on Callum, which is usually seven days although I think there are different types.
“We saw him back in the dressing room at half-time and he seemed bubbly and bright and was talking. He was just disappointed that he had to come off but we’ll just have to see how he is.”