The Spanish giants always had an uphill task on their hands as they needed to overturn a four-goal deficit from the first leg.
However, it was not to be for Barca as goals from Arjen Robben, Thomas Muller and an own goal from Gerard Pique gave the Germans a 3-0 win at Camp Nou to cap a comprehensive 7-0 aggregate scoreline.
"It's a very excessive result compared to what happened over the two legs but Bayern were the better side," said Rosell after the match.
"In my opinion, we lost the tie over in Munich and we had too big a deficit to redress the balance here. It was always going to be tough.
"I think that Bayern are currently the strongest team in Europe and that they will win the final, although in football you never know.
"I don't think that Spanish teams did all that badly in the competition this season. Now we must wait for next season and see what happens.
"I would like to congratulate Bayern because they were clearly better than us and deserve to be in the final."
Rosell insists that Barcelona can be 'proud of their efforts' and added: "Obviously Lionel Messi's absence was felt but the rest of the players stood up to the challenge. I am proud of the squad, the technical staff and the fans."
On Messi's absence he added: "I agree with what Tito said about him. When you have the best player in the world but he is not out on the pitch, you really notice it. Having said that, I am very proud of our coaching staff - we showed this evening that we are a club which is gracious in victory and in defeat."