Manchester United boss Sir Alex Ferguson has no concerns over Wayne Rooney's sudden goal drought.

Rooney, 22, is suffering a barren run by his high standards with just one goal in his last four games.

Cristiano Ronaldo, by comparison, has hit eight in four and has a total of 27 goals to Rooney's 10.

Rooney missed two gilt-edged chances in the 2-0 win over Portsmouth.

And Ferguson said: "He was working too hard on Wednesday night and I think that cost him the opportunity of getting goals.

"I've had to tell him to stop dropping back into midfield so much because Paul Scholes and Michael Carrick can do the work there and control that.

"I wish every player had that same desire. It is a joy to see a young lad with that natural enthusiasm.

"Don't worry, he will be banging the goals in again soon."