Cork City manager John Caulfield believes that Rosenborg’s quality of play was at a different level to that of his Cork City team.
"The level across Europe is high," Caulfield told RTÉ Sport.
"You see where we are ranked, you can’t look at the honesty and the work rate of our lads.
"It comes down to the sheer quality of keeping the ball and moving the ball, their pace and strength was at a higher level and that’s the difference, if you switch off you get punished."
His side conceded two first half goals and then a third in the second-half, losing the tie 5-0 on aggregate.
"In the 25th minute in our last three European matches we’ve conceded and conceded three soft goals and that is disappointing, if you look at their pace and their movement, they are a really good team."
Caulfield’s focus is now back on domestic matters and Sunday’s game against St Patrick’s Athletic.
"That's our next most important game, it's about trying to retain our League and we are still in the Cup. Europe is fantastic, we got two tough draws this year, in both ties the teams proved to be better than us and there is no disgrace in that."