Bruce could be without three centre-backs for Saturday's Premier League match against Bolton at the Stadium of Light, with Anton Ferdinand last weekend joining Michael Turner and Titus Bramble on the injury list. It was initially feared Ferdinand could be out for up to a month with a hamstring strain but the club now believe the problem could be related to his back and the 25-year-old will have a fitness test on Friday to determine whether he can feature on Saturday. Defence has been one of the keys to Sunderland's good form this season, and they will be bidding for a third consecutive clean sheet as they look to leapfrog Bolton, who currently sit two points and one place ahead of them in sixth. No Premier League club has had more shut-outs this campaign, with last weekend's 0-0 draw at Fulham making it eight, moving Sunderland level with Manchester City and Chelsea. Looking ahead to January, Bruce said: "You can't go and replace people just because they've got a bit of an injury. "If two or three go down and they're serious then maybe I'll look at it but I'm very, very pleased with what we've got and what we've done over the last 18 months. "I think I need time to work with the players that we've got. We've got a lot of young players and I can't see myself being that busy." With Turner and Bramble both likely to be out until February, Bruce is relying on Ferdinand and Ghanaian John Mensah to keep things tight at the back. Mensah is in his second season on loan from French giants Lyon after impressing in between spells out injured last term. This campaign has again seen the 28-year-old spend time on the sidelines with a dislocated shoulder, and Bruce is now hoping his problems are behind him. "The more he's out there, the more he trains, the more he plays, the better," continued Bruce. "Last week he was easily our best player. "I've said it many times, there are not many better defenders than John Mensah around when he's fit so it's important, with what we've got missing at the moment, that John stays healthy and stays fit." If Ferdinand does not make it then Nedum Onuoha is likely to move inside to play alongside Mensah, meaning Egyptian Ahmed Elmohamady could again deputise at right-back. Bruce has mainly used the 23-year-old as a winger following his loan move from ENPPI in the summer, but he plays in defence for his country and filled in there when Ferdinand sustained his injury at Fulham last weekend. "He's good in the air and in fact he's probably a better full-back than he is a wide player, so it's an option," added the Sunderland boss. After Bolton, Sunderland face Manchester United, Blackpool, Blackburn and Aston Villa in quick succession over the Christmas and New Year period, and Bruce expects those games to go a long way to determining whether they can stay in the hunt for a European place. He said: "December and January usually sorts out where you're going to be. We've got four games in something like eight days, so that's a huge part. Can we get into the top 10 and compete for Europe? Why not."
