Barca won 2-0 thanks to a Raphinha penalty and a Lamine Yamal goal, as Villarreal lost defender Renato Veiga to a red card midway through the first-half.
Marcelino also said, "I think we'll all agree. We saw a great Villarreal, a tremendous team. We had the chances but we didn't take them. I don't know, what's the difference between that penalty incident and Joan (Garcia) getting up to stop one of our players from going for the ball? The team stuck to the plan, they had possession but no chances, they were very uncomfortable. Our chances were clearer.
"I think Barça's standout player today was the goalkeeper. I saw Joan García's play and it looks like a penalty to me. I respect any other opinion."
He continued: "We're in that situation that happens during the season where the opposition doesn't create many chances but still manages to hurt you. We can't stop believing. I knew the team would be fine. The team hadn't lost its form or its competitive edge. I can only congratulate my players. Even with ten men, we competed and created chances. What more could I ask for?"
On Veiga's red card, Marcelino also said: "We made an avoidable mistake with the sending-off, which greatly affected the game. I was telling the referee that if he gives a yellow card and then VAR calls him for a red, I don't know what happens the other way around. For me, it wasn't a sending-off. The impact was strong.
"Well, from another angle I have more doubts. Yesterday I see a tackle from higher up. This one was along the ground. I don't think the tackle was serious. There's no ankle twist. If the referee thought it was serious... with the spectacle we were seeing. 38 very good minutes. To leave a team with ten men..."