Girona's Pablo Maffeo was tasked with man-marking Lionel Messi in his side's 3-0 loss to Barcelona on Saturday.
The full-back, from Sant Joan Despi, revealed after the game what Messi said to him during the Catalan derby at Montilivi.
"When you cover Messi, you have to think that he's a normal person, that he has two legs like everyone else," on-loan Manchester City defender Maffeo said.
"Messi said to me 'I've got you here for the whole game' and I responded 'You're the best in the world, what am I going to do.'
"He asked me a couple of things: if I was on loan from Man City and how old I was. He was very humble.
"We were talking because I was stuck to him the whole match. There was no bad feeling or anything funny. He’s the best player in the world and if you don’t stick to him, he can score at any moment.
"I had to be with him and to stop him touching the ball. It’s difficult, not just in terms of the football, but physiologically. I am grateful for the confidence the coach showed in me."
However, Maffeo didn't ask for Messi's shirt: "A friend of mine wanted Ter Stegen’s so I asked for his. Messi is the best in the world, but friends come first."