"For a winger like Cristiano to have 22 goals at this stage is fantastic, absolutely incredible," Fergie told the Daily Mirror.
"At the start of the season people were wondering whether he could match last season's total of 23, and you had to say 'well why not?' He's a young lad who's improving all the time.
"He's always practising and his decision-making is getting better all the time. There's no reason why he can't carry on scoring at this rate."