The Latics were knocked out of the Europa League on a night when both teams were awarded a penalty and had a man sent off.
Speaking after the match, Rosler felt that the occasion was perhaps too big for the referee and added that his team would have won were it not for Chris McCann's red card.
"The referee didn't have his best day, he influenced the game in a massive way. He looked to me very inexperienced, he made a lot of errors," he told BBC Sport.
"I can only say I'm very proud of my players, not only with the way they played but they never gave up. We attacked more and in the last minutes it was one-way traffic.
"I think everybody in the stadium would agree that we were the far better team. With no sending off, we would have won the game."
Wigan are back in Championship action against Bolton Wanderers at the weekend.