• Too much Messi? Nobody else in the Argentina squad has scored more than one goal or has accumulated more than one expected goal (xG). Messi has three goals and 3.09 xG so far.
• Croatia lacking firepower: Andrej Kramaric has accumulated the most xG for Croatia at the World Cup with just 0.88, and as a team, Croatia has accumulated just 4.44 xG over four games.
• Problems ahead for England's center-backs: No defender remaining in the competition has accumulated heavier positioning downgrades than Harry Maguire, while his center-back partner John Stones is tied for fourth-worst in the same category.
Estimated reading time: 4 minutes
Eight countries have now booked their place in the World Cup quarterfinals and find themselves just three games away from ultimate glory. Some have dominated the tournament so far, while others have shocked international powerhouses en route to the knockout stages, but every team will go into the round with the belief that they can lift the World Cup in 10 days' time.
Before the games begin, we've used the PFF grades and data to identify each team's biggest weakness heading into the quarterfinals.
Argentina: An over-reliance on Lionel Messi
Relying on arguably the greatest player of all time isn’t exactly the worst place to be, but Messi will likely need more attacking help if Argentina is to lift the World Cup for the first time since 1986.
Nobody else in the Argentina squad has scored more than one goal or has accumulated more than one expected goal (xG). Messi has three goals and 3.09 xG so far.
Brazil: Issues at full-back
Against South Korea, Brazil played right-back Danilo at left-back and centre-back Eder Militao at right-back. They were eventually replaced by center-back Bremer and a 39-year-old Dani Alves. Alex Telles has been ruled out of the tournament, and Alex Sandro missed out against South Korea through injury.
Brazil countered their full-back issues against South Korea by shifting to a back-three in possession, but their lack of available options come to haunt them against higher-quality opposition.
Croatia: Scoring Goals
Croatia has scored just five goals, the least among the remaining teams at the World Cup. Center-forward Marko Livaja has played the most minutes among his peers in this tournament but has a PFF shooting grade of just 55.2 on five shots, 63rd among forwards. Bruno Petkovic started up front against Japan, but he is yet to take a shot at the World Cup.
The issues at striker are emblematic of a wider attacking problem: Andrej Kramaric has accumulated the most xG for Croatia at the World Cup with just 0.88, and as a team, Croatia has accumulated just 4.44 xG over four games.
Despite keeping clean sheets in their last three matches, England has yet to be truly tested and could be vulnerable against higher-quality attacking sides, starting with France on Saturday.
No defender remaining in the competition has accumulated heavier positioning downgrades than Harry Maguire, while his center-back partner John Stones is tied for fourth-worst in the same category.
A switch to three at the back may be necessary to cover up the deficiencies of Stones and Maguire.
France is the hardest team to find a weakness for, but captain Hugo Lloris may be that weak link for the defending champions. Lloris has just a 56.2 shot-stopping grade at the World Cup, by far the lowest among no. 1 goalkeepers left in the quarterfinals. Backup Steve Mandanda hasn't fared better, either, having earned a 49.2 shot-stopping grade, so France will need their leader to step up his performances if they are to retain the World Cup.
Morocco: Lackluster Attack
Morocco relied on tactically sound, aggressive defensive performances to advance to the quarterfinals for the first time, but they will have to improve their attacking output if they want to become the first African team to win the World Cup. They have accumulated an xG total of just 2.2 over their four matches. They have managed to convert the few chances they do create, scoring six goals, but will need more to go all the way.
Netherlands: Conservative playstyle
Netherlands coach Louis Van Gaal has chosen a pragmatic approach so far. He can argue it’s working, given that his side reached the quarterfinals, but inviting pressure against the likes of Argentina and potentially Brazil is a risky and possibly unnecessary strategy for a side full of technical quality. Having around 40% possession against the USA, the Orange conceded the most shots (18) and the second-most non-penalty xG of any team to go through in the round of 16.
Portugal: Selecting their strongest XI
Portugal finally addressed their biggest weakness ahead of their round of 16 match against Switzerland, and Fernando Santos'men were rewarded with a 6-1 victory.
The fact is that Cristiano Ronaldo has underperformed this World Cup. He has a PFF shooting grade of just 56.0, 61st among forwards, and no player has had their movement downgraded more this World Cup.
Ronaldo’s replacement against Switzerland, Gonçalo Ramos, scored a hat-trick and has earned a PFF shooting grade of 89.9, fourth at his position.
Dropping Ronaldo — the highest goalscorer in International football history — was a big call, and if Santos can maintain his nerve and select the best team, Portugal will be a formidable contender.