Milan were beaten 4-0 and went out 4-2 on aggregate.
"We canâ€™t put all the blame on Niang. If he had scored, it wouldâ€™ve been a different game, but this is football and you only get one chance,â€ť said Flamini.
â€śBarcelona had a great performance, showed all their quality and are among the best teams in the world.
â€śWe tried to play, but it was so difficult for us today. Perhaps we were a little nervous at the start, as we gave the ball away many times and didnâ€™t play the way we usually do.