Japan vs. Costa Rica (Sunday, 10.00am)
Hiroki Sakai is a doubt for Japan due to the injury that he picked up against Germany, and he was forced to miss training on Thursday with the issue.
Takehiro Tomiyasu would be Sakai's natural replacement, although the Arsenal defender also missed training on Thursday, so he will need to prove his fitness over the next 24 hours or so.
Asano came off the bench to score the winner against Germany, and he could now come into the starting side for this match, potentially taking the place of Daizen Maeda.
Yuto Nagatomo was also replaced in the second half of the team's first match of the tournament, but the 36-year-old is fit to start this game, and he should again line up at left-back.
Costa Rica, meanwhile, have not reported any injury concerns from their defeat to Spain.
Head coach Suarez is expected to resist the temptation to shuffle his pack from the loss to La Roja, but there could be a change at the back, with Kendall Waston potentially coming in for Carlos Martinez.
Bryan Ruiz and Alvaro Zamora are also among those pushing for spots in the side, but Joel Campbell should again be joined by Anthony Contreras in the final third of the field, and there is no question that the manager will be looking for a much-improved performance in this contest.
> How Japan could line up against Costa Rica
> How Costa Rica could line up against Japan
Belgium vs. Morocco (Sunday, 1.00pm)
Though Roberto Martinez has already declared his hope that star striker Romelu Lukaku will be available this weekend, Belgium's leading scorer is facing a race against time to be involved. The 29-year-old has been mostly sidelined since the end of August with a hamstring injury and may not be fit enough even for a place on the bench until the final group game against Croatia.
In Lukaku's absence, Michy Batshuayi is favourite to deputise up front again, having both scored the only goal last time out and established an impressive international record to date.
Lois Openda, of Ligue 1 club Lens, offers another option during the second half, while Leandro Trossard made a cameo against Canada and has been in excellent form for Brighton & Hove Albion. The latter will find it tough to displace captain Eden Hazard, however.
Martinez is expected to retain the formation which he deployed on Wednesday, but Thomas Meunier and Amadou Onana are in contention for promotion to the starting lineup at wing-back and in central midfield respectively.
Meanwhile, Morocco's midfield fulcrum Sofyan Amrabat will play again but carries a booking over from the Croatia game, as Walid Regragui names a similar XI to that which kicked off the tournament.
Sevilla goalkeeper Yassine Bounou should therefore line up behind Achraf Hakimi, Romain Saiss and Nayef Aguerd at the back, and Bayern Munich full-back Noussair Mazraoui is likely to join them, despite being stretchered off in midweek.
Though the former Ajax man landed heavily on his side, it is believed he sustained only a minor muscular injury; Yahia Attiyat-Allah stands ready if required.
> How Morocco could line up against Belgium
> How Belgium could line up against Morocco
Croatia vs. Canada (Sunday, 4.00pm)
Croatia were handed a scare when attacker Nikola Vlasic had to come off at half time in the draw with Morocco due to discomfort, but the West Ham United man has not sustained a serious issue and has been put through his paces in training.
Whether Vlasic is ready to start again is another question entirely, so either Mario Pasalic or Mislav Orsic could force their way into the attack here, with Andrej Kramaric expected to hold his place despite pressure from Marko Livaja.
Dalic has no other injury concerns to work around for Sunday's game, where Rennes midfielder Lovro Majer's attacking impetus will most likely be required from the bench again, with Luka Modric, Marcelo Brozovic and Mateo Kovacic seemingly nailed-on to start again.
Meanwhile, Canada star man Davies battled back from his hamstring injury to make the starting lineup in their opening loss to Belgium, where Milan Borjan and Stephen Eustaquio were also given the green light to feature despite previous concerns over their fitnesses.
Herdman has no fresh worries to report from matchday one and should keep any alterations to a minimum given the manner of his side's performance, but Cyle Larin should feel in with a strong chance of coming into the attack in place of Junior Hoilett.
Atiba Hutchinson is set to win his 100th cap for Canada this weekend - becoming the first ever player from his nation to do so - but if his 39-year-old legs are in need of a break, Ismael Kone and Jonathan Osorio are on hand to deputise.
> How Canada could line up against Croatia
> How Croatia could line up against Canada
Spain vs. Germany (Sunday, 7.00pm)
Spain boss Enrique may decide to name an unchanged starting lineup on Sunday following their thumping win over Costa Rica, with attacking trio Torres, Asensio and Olmo all in line to retain their places in a fluid front three.
Eighteen-year-old starlet Gavi, who made World Cup history with his goal on Wednesday, is expected to start again alongside fellow Barcelona midfielders Pedri and Sergio Busquets.
Aymeric Laporte was surprisingly joined at centre-back by Manchester City teammate Rodri, who may keep his place at the heart of the defence ahead of Pau Torres and Eric Garcia.
After replacing the injured Jose Gaya in Enrique's 26-man squad, Alejandro Balde came off the bench to make his senior international debut against Costa Rica, but the 19-year-old is set to begin on the bench once again on Sunday, with Jordi Alba poised to start at left-back.
As for Germany, Leroy Sane missed the defeat against Japan due to a knee injury and the Bayern Munich winger remains doubtful for Sunday's game, despite returning to training in the last few days.
Flick is unlikely to make too many changes, if any, to his starting lineup, with a back four of Niklas Sule, Antonio Rudiger, Nico Schlotterbeck and David Raum set to remain intact, protecting captain Manuel Neuer between the sticks.
Gundogan will hope to keep his place in centre-midfield alongside Joshua Kimmich, with the Man City man looking become the first player since Miroslav Klose in 2002 to score in both of Germany's first two matches at a World Cup.
Kai Havertz struggled in the final third last time out and his position up front could come under threat from Karim Adeyemi, Niclas Fullkrug and Youssoufa Moukoko.
> How Germany could line up against Spain
> How Spain could line up against Germany