Ronaldo is rumored to be ready for an early return against Villarreal in the Champions League on Wednesday, as well as against Chelsea in the League on Sunday.

United manager Sir Alex Ferguson said: "He's been making great strides in the direction towards first-team football.

"Ronaldo is training now, he's with the first team and he's aiming to be a substitute at Chelsea on 21 September. He's come on leaps and bounds.

"I think we mentioned a couple of weeks ago he was making rapid progress in terms of overcoming the injury problem he had and the training he's been doing with the physios and Tony Strudwick the fitness coach."

United will be without Nemanja Vidic for the Chelsea match after he was sent off against Liverpool on Saturday, and Michael Carrick is also likely to be out after injuring his ankle in the same match.