Liverpool midfielder Gini Wijnaldum rates Real Betis veteran Andres Guardado as his toughest opponent.
Wijnaldum clashed with Guardado during the 2014 World Cup as Holland met Mexico.
"The toughest opponent I've ever played against is Andres Guardado. When we met Mexico for the World Cup, it was really hot and I faced him in that match," said the Dutchman.
"It was incredibly hot then, and he just kept running. It was really hard for me - and then he is a really good football player.
"With the ball he was really good. It was a big job to stop him. The heat made it harder than usual, but we won anyway."