Wolves boss Nuno Espirito Santo disappointed after Thursday's loss to Braga at Molineux.
Ricardo Horta's effort saw the Premier League club lose in what was their first appearance in the main stage of a European competition since 1980
Speaking after the game, Nuno said: "It is difficult to break down a team. We didn't create much but the chance they had they got it. It's a tough game. We have to keep on going.
"All the goals are mistakes. If there was perfection there would be no goals. We have to remain calm and move on.
"We controlled the game and managed well but one of the things we have to improve is to be patient and find a way to break down teams. Individually and as a team we have to raise our standards again.
"On Sunday we have another challenge [against Crystal Palace]."