Stoke boss Tony Pulis is waiting to hear the extent of Marc Wilson's injury after he had to be taken to hospital.
It was initially thought Wilson could have suffered a suspected broken leg after he appeared to twist awkwardly while going for the ball with Steven Fletcher.
Pulis told Sky Sports: "He's been sent straight off to hospital so we will wait and see. We're hoping fingers crossed that there's nothing really critical but we won't know until later on.
"The one thing I will say, there was no challenge involved there. I think Marc's done that himself."
Pulis was left to bemoan Stoke's luck after they failed to find the breakthrough against the Black Cats.
He added: "If you have a look at the game on a whole we did have the better opportunities and the best chances and you need a break.
"You need one to drop for you. If we'd have scored one then it's a different game."
He added: "We haven't had much go our way this year. And like I say, the opportunities first half, we've watched a few of the corners and the set-plays there, inches away but that's the difference between success and failure at times.
"It was a competitive game. Martin (O'Neill)'s brought (Lee) Cattermole in for (Stephane) Sessegnon and made it really, really tight in midfield and difficult and they defended very well at times.
"But we had the opportunities and when you get those opportunities you need a little bit of luck as well and they break the right side for you and you put them in the back of the net."