The Brazilian striker, who last played for Internazionale on 17 January, came on as a second-half substitute in the Italian Cup semi-final second leg against Parma.
Ronaldo missed Inter's 2-0 European Cup quarter-final first leg defeat at Old Trafford due to chronic tendinitis of both knees. However, he gave the Italian club hope of making the return match a week today with some typically stylish moves during a 30-minute run-out.
United may take come comfort from the fact that his presence was not enough to prevent Inter losing 2-1 on the night and 4-1 on aggregate.
Alex Ferguson yesterday used United's European campaign to aim a well- placed dig at the Arsenal manager, Arsene Wenger, in their continuing battle of minds. The two Premiership adversaries are again trying to unnerve each other as the pursuit of honours reaches a climax.
The United manager began the latest exchange when he claimed his side's goalless draw with Chelsea in the FA Cup on Sunday made the Gunners favourites for the title. Wenger countered Ferguson by claiming the advantage was with Old Trafford's treble-chasing team.
Wenger also offered to swap positions with the Scot if he was so confident that the champions have the advantage. Now Ferguson has hit back at the Frenchman, saying: "I can understand his offer because we're in the Champions' Cup and they're not."
Ferguson and Wenger's psychological war will be bound to escalate if United beat Chelsea in tonight's quarter-final replay and set up a semi-final date with the Gunners at Villa Park on 11 April.
Ferguson is expected to revert to a more familiar 4-4-2 formation for the Stamford Bridge tie. Dwight Yorke and Andy Cole should return to spearhead the attack, Jaap Stam is available after suspension and Ryan Giggs returns after a nose operation.Reuse content