Portugal have the edge over Uruguay's all-star attack thanks to Cristiano Ronaldo's brilliance, according to right-back Cedric Soares.
The sides meet in Sochi on Saturday, with Uruguay the only team alongside Croatia from the six completed groups at Russia 2018 to boast a 100 per cent record.
La Celeste's strength is based on the twin pillars of Luis Suarez and Edinson Cavani up front and Atletico Madrid centre-back pairing Diego Godin and Jose Gimenez, who must face up to a familiar foe.
"They have great players like we do, but we have the best player in the world," Soares told FIFA.com, with Ronaldo set to equal ex-Germany captain Bastian Schweinsteiger's record of 38 appearances combined in World Cup finals and European Championships.
"We will study them. They're a strong team but we also have our qualities and we will try to win the game."
Ronaldo began the tournament in spectacular fashion, with his stunning free-kick completing a hat-trick and snatching a 3-3 draw against Spain at Fisht Stadium.
Ahead of their return to the Black Sea coast, the more prosaic feel that ran throughout their slow march to Euro 2016 glory has returned, with Ronaldo giving Portugal an early lead they hung on to against Morocco before Ricardo Quaresma's sublime strike illuminated a VAR-fuelled 1-1 draw with Iran.
Uruguay, by contrast seem to be easing their way through the gears after an unblemished group stage that suggests the best is yet to come.
Gimenez and Suarez were respectively responsible for unremarkable 1-0 wins over Egypt and Saudi Arabia but the Barcelona striker and Cavani were both on target as hosts' Russia were exposed to a gulf in class and a 3-0 defeat.
"We are facing a very strong and powerful team," Inter midfielder Matias Vecino, who has started every game so far at Russia 2018, told FIFA.com
"The match will be defined by details and we will try to limit their forwards."
Portugal left-back Raphael Guerreiro, winger Gelson Martins and midfielder William Carvalho all sat out training on Thursday with minor muscular complaints.
Gimenez is back with his Uruguay team-mates after a thigh injury ruled him out against Russia.
PLAYERS TO WATCH
Uruguay – Luis Suarez
Suarez was frustrated during the opening game against Egypt but appears to be coming to the boil just at the right time – he has managed to avoid any further World Cup controversies so far as well, following 2010's handball and 2014's biting.
Portugal – Cristiano Ronaldo
The unquestionable driving force and inspiration for Fernando Santos' men, Ronaldo flew out of the blocks in this tournament but missed a penalty and might have been sent off in a tempestuous encounter with Iran. It would be foolish to bet against him getting swiftly back on track.
KEY OPTA FACTS
- Luis Suarez has scored seven World Cup goals for Uruguay, second only to Oscar Miguez (eight) – Suarez scored a brace against South Korea in his only previous appearance in the round of 16 back in 2010.
- Cristiano Ronaldo has so far failed to score a single goal for Portugal in the knockout stages of the World Cup: 424 minutes, 0 goals.
- Penalty shoot-outs excluded, Portugal have lost only one of their last 17 games at major tournaments (W8 D8), a 4-0 defeat against Germany at Brazil 2014.
- All five of Uruguay's goals at Russia 2018 have been scored from set-pieces (three from corners, 1 from direct free-kick and 1 from an indirect free-kick). Meanwhile, three of Portugal’s last four goals have come from outside the box.
