The Yellow Submarine won 3-2 to secure fifth place and Champions League qualification for next season.
Marcelino said afterwards: “It's the perfect addition to the achievement that this squad, this club, and these fans have achieved. It's not the same, although the meaning is. You come to this stadium and play against the champions, who hadn't lost this year, although it's true that they can disconnect a bit after winning the title.
"But we're very satisfied after having achieved this, beating a great Barça here, who gave us the points we needed and taking a big lead over Betis. We're very happy. Few of us could have imagined we'd be able to qualify for the Champions League back in July because we were coming off a very difficult season.
"I think we've planned and built very well. We've worked hard, and the squad has been supportive and has been a team. And the teams with whom they achieve their goals. I thank them on behalf of myself and the entire staff.”
"We're back in the Champions League"
The coach also said: “The way football is today, being in the Champions League gives you a boost, also financially. If we get it right, we can build a more competitive team and enjoy the best club competition in the world.
"Not long ago, Villarreal reached the semi-finals, but cycles come and go, and last year was difficult. Fortunately, together we were able to turn things around and we're back in the Champions League.
"If we didn't finish fourth, it's because there were four teams better than us, and we congratulate them, but we've pushed Athletic until today. In November and December, we suffered a lot from injuries."