MANCHESTER (AFP) - England goalkeeper Ben Foster has been told he will make his Manchester United debut against Derby County on Saturday -- just a week after returning to reserve team duty following a ten-month cruciate ligament injury lay-off.

United manager Sir Alex Ferguson is without both first-choice goalkeeper Edwin van der Sar due to injury and back-up stopper Tomasz Kuszczak for the trip to Pride Park following the Pole's dismissal in the FA Cup quarter-final defeat against Portsmouth last Saturday.

Foster, 24, has yet to make a senior appearance for United, despite arriving in a one million pounds (two million dollars) move from Stoke City in 2005.

And although he impressed on United's pre-season tour of South Africa in 2006, his first-team football over the last two seasons has been played at Watford during two season-long loan spells at Vicarage Road.

However, his form for Watford earned him an England debut in the friendly defeat against Spain in February 2007 and Ferguson admits that he has no qualms about thrusting Foster into the United first-team for the clash against Derby, the Premier League's bottom club.

"I was planning to send Ben out on loan last Monday, but he will now be making his debut for us at Derby because of Edwin's injury and Tomasz Kuszczak's suspension," Ferguson told reporters here Friday.

"Ben has been out of action for almost a year and he has only had one reserve game in which to prove his fitness, so it will be a big challenge for him," the Scot added.

"But he has done really well in training and he has a fantastic presence, so I am sure that he will be okay.

"He had his knee operation last June, his rehab has gone well and he has been training with the rest of squad for over a month now, so there are no question marks over his fitness levels."

United can reclaim top spot in the Premier League from Arsenal if they beat Derby and then win their game in hand against Bolton Wanderers at Old Trafford next Wednesday.

And Ferguson admits that the time has come for United to find the form that will ensure they retain their league title come the end of the season.

"We have ten games left to play now, so we have to put our foot down and move on.

"Derby are struggling, but you can only look at your own team and make sure that you get the performance and the result.

"The teams at the top have been dropping points -- ourselves, Arsenal and Chelsea -- so if we can get ourselves on a consistent run, then we will give ourselves a better chance.

"It is important to get that consistency and not drop from a good level of performance. We have a tough programme between now and the end of the season, but then Arsenal and Chelsea have got it equally tough.

"It won't be easy and I can see it being very close and it could even go to the last game, but we have to give ourselves a chance."

Louis Saha is set to return for United after training this week following the knee injury, sustained in the pre-match warm-up, that forced him out of the Portsmouth game last Saturday.

But club captain Gary Neville is unlikely to make the squad, despite playing 73 minutes in the reserves on Wednesday to boost his fitness following 12 months out with ankle and calf problems.