The Japan star became the first Asian player to score a treble in the Barclays Premier League as he launched United towards a 4-0 win over Norwich at Old Trafford.
"It was a brilliant day for him," said Ferguson. "He is a good finisher. His second goal was composed and intelligent, his last was brilliant.
"He missed that period of football in October and November that set him back a bit. He is gradually getting his form back but next year he will be far better, you will see a really good player then."