The Portuguese winger, voted England's double Footballer of the Year last season, has already scored 23 times for the Premier League champions in all competitions this season and currently tops the scoring charts with 17 goals.
Despite operating on the wing for United, Ronaldo has still shown an incredible for goals this season and, with Sir Alex Ferguson's team still going strong on three fronts in the league, FA Cup and Champions League, the former Sporting Lisbon youngster could record an awesome tally if he continues in his current vein of form.
The 22-year-old, currently enjoying United's mid-season break in Saudi Arabia, is set to face Spurs at Old Trafford in the FA Cup fourth round on Sunday and boss Ferguson admits that there are no limits on Ronaldo's goalscoring abilities.
Ferguson said: "With Ronaldo having scored 23 goals already, there is the potential for him to score 30 this season without question. He is not that far off and he has a strong chance of doing that.
"I'm sure that he is capable of scoring 30 league goals, though. I think that is a different matter entirely.
"Achieving that would be more difficult and I don't think that it will happen. It is a big ask, but if he does manage it, I'll pay him more money!"