Ole Gunnar Solskjaer said he had no time to study Celtic in preparing Molde for their 3-1 Europa League Group A victory over the Scottish champions.
The former Manchester United striker returned as head coach on Wednesday and said he was leaving most arrangements to former caretaker Erling Moe.
"I didn't really bother about Celtic because it's my second day back," said the head coach.
"And I expected a lot from my boys because I know they are capable."
Solskjaer led Molde to back-to-back domestic titles during his previous three-year spell in charge and many of the same players remain at the club.
They are poised to relinquish their title this season and sit in seventh place, but the coach praised the way they had adapted their game to a more counter-attacking style for the European stage.
BBC Sport