Manchester United boss Sir Alex Ferguson is delighted with their current firepower.

Although striker Wayne Rooney and Robin van Persie have started most of the games this season, Ferguson was in no doubt that having fellow-forwards Danny Welbeck and Javier Hernandez in the squad was vital.

"Having four is a definite advantage," said Ferguson, whose team won the treble in 1999 with an attacking quartet of Dwight Yorke, Teddy Sheringham, Ole Gunnar Solskjaer and Andy Cole.

"It is difficult to manage but they didn't complain too much back then as long as they got their share of playing and they all made their contribution.

"Hopefully this will apply with the players again. But they will all contribute this season - there is no question about that."