SUNDERLAND face having just one fit central defender for Saturday’s crucial trip to Birmingham City.

Ghana captain John Mensah has been ruled out for “at least three weeks” with a groin tear, increasing the pressure on Anton Ferdinand to make a quick recovery from his hamstring injury.

Like Mensah, Ferdinand picked up a problem in the 3-2 defeat to West Bromwich Albion. With Titus Bramble ruled out for the season, Michael Turner was the only fit specialist centre-back in training yesterday. Turner is feeling his way back to fitness after five months out with knee ligament damage.

Regular right-back Nedum Onuoha has deputised in the centre this season, but moving him would cause further disruption, with Ahmed Elmohamady likely to take his place.

Manager Steve Bruce has tried nine different combinations at the heart of his back four this season, and without Ferdinand he will have to turn to a tenth. At times this season he has asked players to play through injury, or return before having sufficient time to get up to speed following long lay-offs.

Perhaps this partly explains the alarming tendency of Sunderland players to suffer recurring injuries.

With that in mind, Bruce will have to be careful with Ferdinand, but it is not just a lack of alternatives which increases the urgency.

The Black Cats have lost seven of their previous eight games, drawing the other. The relegation-threatened Blues will leapfrog them in the table with a two-goal win, as their neighbours the Baggies did last week.

Mensah’s injury has been diagnosed as a grade two adductor tear. Grade three is the most serious, and Sunderland expect to be without the 28-year-old for “at least three weeks”. Mensah is on a season-long loan from Lyon, and Sunderland will review his injury record before deciding whether to make the arrangement permanent.