Van Nistelrooy rumbled by defenders: Allardyce

Ruud van Nistelrooy has hit a goal drought because premier league defenders have got wise to the Manchester United striker, according to Bolton Wanderers manager Sam Allardyce.

The Dutchman, who cost United 19 million pounds in 2001, bagged 36 goals in all competitions last season but has not scored in open play in domestic football since a 3-0 win over Chelsea last April.

Allardyce, whose side scored a second consecutive victory over United at Old Trafford on Wednesday, told British papers on Friday: "It's common with every player in the premiership -- they burst on to the scene as an unknown commodity and they get found out."

Looking at his own main striker, Allardyce added: "Michael Ricketts has found it hard because he is marked a lot tighter and van Nistelrooy is the same.

"We thought van Nistelrooy would play on his own but he had Ole Gunnar Solskjaer alongside him. If you deny United space behind you then you have a chance.

"For that reason, they found it difficult to break us down. As soon as United have the ball we would drop to our 18-yard line and not let them get behind us.

"United are at their most dangerous when you are attacking them. The moment you leave spaces they will expose them."

Van Nistelrooy's only premier league goal this season was a penalty converted for a 1-0 victory over Middlesbrough.

He also scored once from the spot and also in open play in their 5-0 demolition of Zalaegerszeg in last month's Champions League third qualifying round second leg at Old Trafford.