Manchester United's injury problems mount up ahead of the Premiership leaders' clash with Wanderers on Saturday lunchtime.

Goalkeeper Edwin Van der Sar and key defenders Rio Ferdinand and Nemanja Vidic face fitness battles to be fit for Saturday's derby game.

United kept their treble quest alive at the weekend after surviving an FA Cup scare at the hands of Middlesbrough.

Sir Alex Ferguson's side surrendered a 1-0 lead and then had to come from behind to clinch a replay at Old Trafford next Monday courtesy of Cristiano Ronaldo's 68th-minute penalty.

However, the draw came at a cost with van der Sar undergoing a scan yesterday on a calf muscle damaged during the warm-up, while Ferdinand and Vidic both picked up injuries which could rule them out of the Bolton fixture.

With Ole Gunnar Solskjaer, Louis Saha, Darren Fletcher, Patrice Evra, Mikael Silvestre already sidelined through injury, and midfielder Paul Scholes suspended for the next two matches, including the Wanderers clash, Ferguson will be hoping the influential trio can recover in time.

But, despite the deepening injury crisis, the United boss, who has admitted he wants to stay at the club for another two years, believes the treble dream is still alive.

"We are still there," he said. "The name of the game is to keep winning.

"That is the best recipe and best energy-enhancer of all time, winning. We can handle that.

"Middlesbrough are still in the cup too. We will approach it the way we did today. We will use our squad in the right way."

Wayne Rooney's first goal in eight games had put the visitors in front until Lee Cattermole equalised a minute before half-time.

The Teessiders got their noses in front within two minutes of the restart when George Boateng haeded home, but Ronaldo's 17th goal of the season from the penalty spot sent the tie to a replay.