Atalanta head coach Gian Piero Gasperini says he was sad to see Cristiano Ronaldo leave Juventus for Manchester United in the summer.
Ronaldo re-joined United in August on a two-year contract, with an option for an extension, for an initial £12.86m fee. There remains potential for a further £6.85m in performance-related add-ons.
So far this campaign, the Portuguese has made seven Premier League appearances, netting four times while assisting once including a late winner against Atalanta.
Ahead of the Reds' Champions League second-leg tie with the Serie A outfit on Tuesday, the Atalanta boss described Ronaldo as 'an incredible scoring machine.'
The 63-year-old revealed he was left 'disappointed' with the Portuguese playmaker's return to English football.
"He added value to our league," Gasperini added. "Personally, I was disappointed with his return to England.
"I would prefer if he stayed in Italy because I always want the best footballers to play in Italy - even if it costs me a few conceded goals.
"I can say that he is an extraordinary player, but I have the impression that I'm saying something completely banal."
"What he's doing again at Manchester, you only have to look at his goal on Saturday (against Tottenham) and the others he's already scored, he's an incredible goalscoring machine."
Ole Gunnar Solskjaer's men sit top of Group F on six points after two wins and a draw.
Tuesday's match will take place at the Gewiss Stadium with kick-off set for 8pm.
