Macari said: “I would not want to frighten the Celtic fans but you might want to look back at what happened the last time
“He had been injured and he came back against Fenerbahce with a brilliant hat-trick.
“He was off the leash after about three months and I thought, ‘Rooney will be lucky to get through the 90 minutes'.
“
He also has high hopes that Rooney will score lots of goals for United this season.
He added: “If
“He scored two in the first one against Fulham and has the goalscorer's knack — and he's accurate.
“We've done analysis on him for MUTV and found nine out of 10 of his shots hit the target.
“He almost always tests the goalkeeper and is a cool finisher in the box. Not many players are like that nowadays.”