Sunderland boss Tony Mowbray drops a concerning injury hint ahead of Birmingham City clash

Mowbray is already without Luke O'Nien for the clash at Birmingham City, who picked up his fifth yellow card of the season during the 1-0 defeat to Cardiff City.

Dan Ballard, Aji Alese, Edouard Michut, Lynden Gooch and Ross Stewart are still sidelined with injury, with the hope that they will return after the break.

Asked for an injury update ahead of the trip to St. Andrews, Mowbray said: "There's lots... but none that I can tell you about."

Those injury issues could yet lead to a return to the match day squad for Niall Huggins, who has not featured since the 5-0 win over Cheltenham Town in September of last year.

Huggins has now played two full 90 minutes for the U21 side after building up his minutes, and rejoined senior training this week. It remains to be seen if he will be named in the squad but he is travelling to the Midlands with his senior team-mates.

"The one positive I can mention is that Niall Huggins is back on the grass," Mowbray said.

"He's had some U21 games and has played 90 minutes twice, and he's back training with the first team now.

"Now he's fully back in the first-team and he'll be on the coach travelling with us to Birmingham."

Sunderland currently four points behind John Eustace’s side in the table, seven off the play-offs and four ahead of the relegation zone.