Sunderland have been dealt another injury blow with the news that Dennis Cirkin has suffered a hamstring problem, journalist James Hunter has confirmed.

The Lowdown: Sunderland lose Stewart to injury

Tony Mowbray's team were beaten 1-0 away to Middlesbrough on Monday evening, in what was a lethargic Championship outing from the Black Cats.

Sunderland's night was dealt a big early blow with the news that star striker Ross Stewart had picked up an injury before kick-off, ruling him out of proceedings.

After the game, a fresh fitness update on another star man also emerged.

The Latest: Cirkin also out

Taking to Twitter, Hunter shared Mowbray's comments regarding Cirkin, with the left-back suffering a hamstring issue at the Riverside Stadium:

"Mowbray: 'Hamstring injury for Cirkin. Another one who'll need a scan'."

The Verdict: Big test of resolve

After such a strong start to the season, there is no question that things have unravelled a little for Sunderland, with Alex Neil leaving, two defeats in the space of three matches and injury problems mounting.

This is now going to be a big test of the Black Cats' resolve in the coming weeks, with Stewart and Cirkin both important figures who will be big losses. The latter has been such a strong performer at left-back this season, averaging 2.8 clearances and 1.8 aerial duel wins per game in the league.

Mowbray's men need to battle their way through this tricky period ahead of matches against Millwall, Reading and Watford in the next 11 days, ensuring they remain in and around the playoff positions heading into the international break.