Lokomotiv Moscow midfielder Manuel Fernandes on Monday underlined the importance of Portugal's opening World Cup group game against Spain in an early heavyweight clash in Russia.

The European champions face 2010 World Cup winners Spain in their first Group B fixture in Sochi on June 15, the winner of which will be in pole position to finish top of a section that includes Morocco and Iran.

"It's a very important game for all of us, we're a strong team now and will be playing a very strong team too, one of the top contenders," Fernandes told reporters at Portugal's training base in Kratovo, southeast of Moscow.

"We shouldn't be underestimating the other two teams but Spain is one of the favourites. We also have respect for Iran and Morocco and will not take them lightly."

"Of course we came here to win all our matches in our group, we can't think about anything else," he added. "Our main goal is to go as far as we can."

The 32-year-old Fernandes, who won the first of his 14 caps as a teenager in 2005, is appearing at his first major tournament as Portugal hope to dramatically improve on a group stage exit four years ago in Brazil.

"I'm glad to be here and we're very happy to have the opportunity to be here. It's very well organised and a wonderful venue and team base camp," Fernandes said.

"We'll try to show our strength to its fullest and we have Cristiano Ronaldo.

"Of course he's a very important player for us. We don't depend on how much he scores but on what form he's in. It's very important to play as a team. We got to this stage by playing well together."

Spain arrived at their training base in the southern city of Krasnodar on Thursday, and beat Tunisia 1-0 in their final warm-up on Saturday to extend their unbeaten run to 20 matches.

"I wouldn't single out any player," Fernandes responded when asked who posed Spain's main threat.

"They have a lot of respect for the Portugal team, they think the game will be very difficult, and we think the same about them."