Sir Alex Ferguson has challenged Gerard Pique to prove he is every bit as valuable to Manchester United as his fellow Spaniard Cesc Fabregas is to Arsenal.

Pique and Fabregas came through the youth ranks together at Barcelona. But while Fabregas has made an instant impact, making his Gunners debut at 16 and becoming a first-team regular within a year, Pique was loaned to Real Zaragoza last season.

But now back at Old Trafford, Pique, 20, marked his first Champions League start with the opener in United's 4-0 win over Dynamo Kiev on Wednesday.

And Fergie raved: "We had to tell Gerard his physique was nothing like as advanced as that of Fabregas and that he had to strengthen up.

"He can play centre midfield and right-back, so there will be many more opportunities."