Sunderland boss reveals defender out of Stoke City game

Cirkin was knocked out in the process of scoring Sunderland’s equaliser against Millwall last month, and has continued to experience some symptoms despite initially recovering.

He will be joining in some training over the coming days, but is not yet ready to return to full contact as so is highly unlikely to be in the matchday squad this weekend.

“Dennis, it’s probably still probably a bit up in the air with the concussion protocols,” Mowbray said.

"He’s had a scan and there’s no damage as such, but we have to follow the protocol until he’s fully right.

“He’s still a little bit fuzzy, he doesn’t feel fully right and so at this moment, he might join in bits of non-contact training but nothing where he’s going to challenge for headers or go into tackles. He feels fine within himself but he’s not 100% and he has to be before he can be put back in.”