Porto coach Julen Lopetegui insisted that Mexico's Hector Herrera will have a very important role with the club this year, despite seeing his playing time limited.
"He is a very good player with a great attitude and an ability to compete. I am convinced he will be very important for us this year," Lopetegui said.
"Hector is a player who last year practically played all the time. He has had two years basically with no rest over the summer [World Cup 2014 and Gold Cup 2015]," the Spanish manager said. "And that is a subject that seems unimportant, but it is not."
Lopetegui has two other Mexico players on his team in Jesus Corona and Miguel Layun.
"We are very happy with all of them. They are good players with good character and work ethic and they are improving," said Lopetegui. "We are pleased with their energy and abilities."
The former goalkeeper singled out Layun's growth on defense.
"Miguel is a player who was playing in the League Championship [Watford last season] and played more forward than on the wing. We knew that he had the technique and the physical ability to help us. He has great energy," he said.