"I touch the ball, maybe I touch (the player) after, but it was certain it was not a penalty," Busquets said. "It was strange how quickly the referee gave it when he was coming from the middle of the pitch."
On Barça's off-colour display, he added: "The pitch was not good and it was hard to control the ball. We knew it would be a difficult game, we had seen videos and we knew it would be hard and it was.
"We lost some balls, but we tried to talk on the pitch to find the free man. They were well-positioned, with a line of five and another of four. We had to be careful so they didn't (counter) with pace."
Ahead of the second leg at Camp Nou next week, Busquets finished: "The goal gives us life. We came to win but it was really difficult and we have things to improve.
"I am sure we will do in the return, with our home fans and on a pitch that I am certain will be better and much quicker."
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