The European champions will face Uruguay in Sochi for a place in the quarter-finals after finishing as runners-up behind Spain in Group B.
Uruguay won all three of their group matches, beating hosts Russia 3-0 in their last outing, and are the only team yet to concede a goal at the tournament.
Real Madrid forward Ronaldo has scored four of Portugal's five goals so far, while Barcelona star Suarez netted against Saudi Arabia and Russia.
"I don't think it will be a duel between Suarez and Ronaldo," Alves said on Thursday. "It's a match between the two teams, Portugal and Uruguay, and we'll do everything we can to win."
Portugal survived a late scare against Iran on Monday, as Ronaldo missed a penalty and was fortunate to escape a red card for an elbow.
"At this stage we still believe we have room for improvement," Alves said. "I think we will win, but you can't forget you can only win if you play well and I think we'll play well."
The 36-year-old Alves is at his third World Cup, although the Rangers centre-back has yet to make an appearance in Russia.
"I feel that we're always highly motivated. I think all of us have come here to play and when our moment comes we will be ready for it to help Portugal win," he said.
"I think this Portugal team is ready for everything. We've shown we have the chance to win and if we keep it up this way I think we'll be successful. There are difficult games in store for us though."
Portugal have not lost a competitive match with Ronaldo in the side since the 2014 World Cup, although they were beaten on penalties by Chile at last year's Confederations Cup.
Alves sounded a note of caution following the departure of defending champions Germany.
"Everybody can see that in this World Cup there are no easy games," Alves said. "Germany's fate made it clear what can happen to any strong team."
Uruguay are hopeful Jose Maria Gimenez will return from injury to resume his centre-back partnership with Atletico Madrid team-mate Diego Godin.