Maffeo, on-loan at Girona, was given a man-marking job for the game by coach Pablo Machin.
"If you have to cover Messi, you must think that he's just a human being, a two-legged person, and be focused," said the defender after Barca's win. "Messi said to me, 'You are going to be very busy here'.
"And I said, 'You are the best in the world, I have no choice'."
It was not Messi's only question.
"He asked me if I was loaned from Manchester City, how it was. And how old I was.
"Messi and I were together the whole time, he has asked a few other things. He is a good person."
Maffeo added: "In the morning, the trainer told me that I had to cover Messi constantly."