Cristiano Ronaldo was an unstoppable force the season he scored 42 goals for Manchester United, just as Wayne Rooney is proving to be this season. With Sir Alex Ferguson's none-too-tacit encouragement, United's leading scorer is being backed to pass Ronaldo's mark – he currently needs 10 more goals to equal it, or nine if you count the one he scored in the Community Shield – yet in a real sense it is academic whether Rooney takes his goal tally into the forties or not.

United have already scored more league goals this season than in the whole of the last one. After 30 games they have 70 goals, and you have to go back to 2001-02 to see that total bettered. Last season's final total was 68, and the season before that, the one where Ronaldo chipped in with 31 league goals as part of his overall contribution of 42, they ended on 80. So if Rooney or anyone else in a red shirt can add 10 or more goals from their last eight league matches, beginning with Liverpool at home today, the idea that they are still missing Ronaldo will be statistically exploded.

Liverpool won 4-1 at Old Trafford last season with Fernando Torres and Steven Gerrard traumatising the home defence, yet, even if the pair are now back in harness and returning to full fitness, it is no secret that Rafa Benítez relies on his golden duo to an almost unhealthy extent. What United have proved in spades since the turn of the year is that they are no longer reliant on Ronaldo. The team have moved on.

The season United most missed Ronaldo was the last one, when they still had the player in body but hardly in spirit. A pale shadow of the previous season's incarnation, Ronaldo still managed a highly creditable 25 goals, but United's final league total was the lowest it had been since the meagre 58 in 2004-05, the season after he arrived when, operating very much as a winger, he contributed five goals.

The most remarkable thing about Ronaldo's 42-goal season was that it represented a prodigious total for a winger, although by that stage Ferguson was giving him free rein to come inside, and sometimes selecting him in central positions. While nothing ought to be taken away from Rooney's scoring record this season, it is much more natural for a centre-forward to score the majority of the goals, especially one frequently employed as the sole striker. Rooney has proved he is capable of carrying the United attack on his own, and is clearly enjoying exploiting the space and responsibility left vacant by Ronaldo's departure. It is not all down to Rooney, though such a lion-hearted performer deserves a lion's share of the credit.

After a necessary period of adjustment Antonio Valencia and Nani have stopped looking like over-promoted bit parts and begun to deliver. Park Ji-sung has been in excellent form and United have benefited enormously from the depth of experience they possess in midfield as well as the still under-utilised Dimitar Berbatov, though it is the quality of service from the flanks that is helping Rooney have such an outstanding season.

Nani's part in Rooney's second goal against Milan, the one that killed the home leg just after half-time, could hardly have been bettered by Ronaldo. There was an electric burst of pace down the left then the subtlest of passes inside to put the ball in the exact place where Rooney wanted it and the Milan defence did not. Much of Rooney's new-found heading ability is due to the quality of the crosses Valencia has been putting in. As Ferguson said of the goals against Milan at San Siro, the crossing was so good it would have been harder for the striker to miss.

Valencia seems to have taken a while to settle, perhaps not finding it easy to step up from Wigan and certainly not relishing comparisons with Ronaldo, but, without ever being a like-for-like replacement for his singular predecessor, he is now doing precisely what Ferguson says he expected him to do. He brings strength, skill and a certain amount of style to the United wing and, while he may never threaten any goalscoring records, he knows how to make goals for others.

Statistics based on the last couple of seasons show that Valencia tackles more than Ronaldo used to, and more successfully, crosses more, and more successfully, and creates around twice as many chances. He does not shoot as often and does not score as many goals but that simply makes him a more conventional winger. He is still a very good one.

Risky as it is to make forecasts after last season's upset, while both United and Liverpool have exceptional strikers, United's support cast appears to offer more attacking promise.