BARCELONA, Spain -- Barcelona midfielder Arthur Melo has said he made a mistake by attending Neymar's birthday party in Paris 48 hours before last month's Copa del Rey first leg match against Real Madrid.
Arthur joined Paris Saint-Germain star Neymar as he celebrated his 27th birthday on Feb. 4. He returned to Spain for training the following day and started against Madrid at Camp Nou on Feb. 6, injuring his hamstring in a 1-1 draw.
The Brazil international said he had misjudged the situation and regretted his actions, which sparked a backlash from local media.
"I think I messed up going to Paris, to Neymar's party," Arthur told a news conference ahead of Barca's Champions League game against Lyon on Wednesday.
"Life has these moments. Sometimes you do the right thing, sometimes you make a mistake. I knew what I was doing. I was excited to go, but I am big enough to take responsibility for my actions.
"You learn from your mistakes. I apologised to the coach and my teammates. It was a difficult moment for me, but I am giving all I can. I know there are things to improve."
Arthur has struck up a close friendship with compatriot Neymar since joining Barcelona from Gremio in the summer.
Zinedine Zidane's reappointment as Real Madrid coach has led to an increase in speculation that Neymar could move to the Bernabeu in the summer.
"It's an option he has to weigh up," Arthur said. "As his friend, I have to wish him the best. I don't know what he will decide, if he will continue at PSG or if he will move to another club."
Barcelona's Philippe Coutinho is struggling for form, but doubts over Ousmane Dembele's fitness mean he could start against Lyon and Arthur said he still had a big role to play.
"Coutinho's one of the best players in the world," he said. "We know he's not been at his best in some games, but we all know what he is capable of, how good he is and how much he is going to help us. We all have to back him 100 percent."