Portugal midfielder Adrien Silva is expecting a tough test against Morocco as he revealed coach Fernando Santos is constantly demanding more from the European champions.

Cristiano Ronaldo stole the show with a stunning hat-trick in Portugal's Group B opener with Spain on Friday, securing a share of the spoils from a fantastic encounter in Sochi.

Leicester City midfielder Silva did not make an appearance from the bench, although Santos could well rotate his players for Wednesday's meeting with Morocco, who slumped to a 1-0 defeat to Iran in their opening fixture.

And the 29-year-old insists Portugal will not take their opposition lightly, with Santos instilling a winning mentality. 

"The coach is never satisfied, he wants evolution," Silva told reporters. "We are never satisfied. 

"We are focused on analysing and surpassing the Morocco team. In my opinion, Morocco deserved to have won the game with Iran.

"There are no easy games. We played against a great favourite, we have also created difficulties for our opponents. It was a positive result, but we didn't want a tie."

Silva joined Premier League club Leicester in August 2017, although did not register in time to be able to take part in the first half of last season.

Prior to that move, Silva spent 10 years in Sporting CP's senior set-up, and former club-mates Rui Patricio, William Carvalho, Gelson Martins and Bruno Fernandes are all part of Portugal's squad.

All four players are currently involved in contractual disputes with the club following an attack on Sporting's training ground by a section of the Lisbon side's supporters, and look likely to leave before the start of next season, but Silva claims the group have not been affected by the situation.

"They showed that they were perfectly in a position to play," Silva added.

"They saw each other during the game, they do not even talk [about Sporting] at the moment, they are perfectly fine, they will have a great tournament."