SUNDERLAND, England -- Sunderland's back line took another hit this weekend as central defender Anton Ferdinand suffered a hamstring injury that could keep him out for a month.

The injury was sustained just 11 minutes into Sunderland's 0-0 draw with Fulham on Saturday, and with fellow defenders Titus Bramble and Michael Turner out, Black Cats boss Steve Bruce is short on options in the middle of the back line.

"With him out we're a bit short defensively but we'll have to deal with it," Bruce told the club's website.

"It seems to hit us all in the one position and at the moment our center-halves are dropping like flies.

"Anton will go for a scan and it looks like he'll be out for a month."

Ferdinand has made nine appearances in the league for Sunderland this season, including eight starts.