MANCHESTER (Reuters) - Manchester United manager Alex Ferguson paid tribute on Friday to winger Cristiano Ronaldo's remarkable goal spree this season.

The Portugal international is the Premier League's leading scorer with 21 goals, four more than his league total for the whole of last season.

"It's superb and I think he has cast all doubts aside about whether he could repeat last season's total," Ferguson told a news conference.

"On a couple of occasions this season he has played as a centre-forward and he has got four goals as a centre-forward out of two games, which is a great strike rate.

"But to score those goals (predominantly) as a wide player is phenomenal."

Ronaldo is set to return to the scene of one of his most important goals in a United shirt at Fulham on Saturday.

Twelve months ago this week, he scored a late winner which maintained a seven-match winning run and kept Chelsea at bay in United's successful race to the league title.

"Ronaldo's performance that day was superb and I think it's fair to say that he decided the game for us with his performance," Ferguson recalled.

"It (the goal) was so late in the game that you have to look on it as one of the most crucial victories for us.

"We were a few points ahead of Chelsea but they were plugging on behind us and if you make a mistake it can count so late in the season."

Ryan Giggs will miss the game at Craven Cottage with a calf injury but United have no other fresh injuries worries.

Ferguson hopes to have a fully fit squad by the end of March with defender Mikael Silvestre, out since September with a knee injury, due to resume full training next week.

Goalkeeper Ben Foster, who has been out all season following a knee injury, is expected to make his comeback in the reserves next Thursday.

(Editing by Trevor Huggins)