Sunderland striker Ross Stewart is facing at least six weeks on the sidelines after damaging a thigh muscle ahead of Monday night’s Tees-Wear derby.

The 26-year-old Scotland international, who has scored five goals in seven Sky Bet Championship appearances for the promoted Black Cats, was forced to withdraw from the team for the 1-0 defeat at Middlesbrough after sustaining an injury in the warm-up.

A scan has revealed significant damage and he now faces a period of rehabilitation which could keep him out for between six and eight weeks.

Head coach Tony Mowbray told the club’s official website: “Ross will be out for six to eight weeks – it could be a little longer, but that will depend on his rehabilitation and the way his body reacts.

“He’s a really positive guy and we hope that he will be a quick healer, so we will take it game by game and hopefully he returns quickly.

“It is a blow and now we have to find a way to score the goals, but we will be positive and we will not be all doom and gloom about how we are going to win games and score.

“There are players within the squad who are capable of stepping up and our job is to find a way to win, so that’s what we will do.”

Full-back Dennis Cirkin limped off at the Riverside Stadium with a hamstring strain but he is expected to be back in action sooner than Stewart.

Mowbray said: “Dennis will be out for one to two weeks. It is as slight an injury as you will see, so he should be back in action within a fortnight.”