Germany could face an ignominious first-round exit from the World Cup in Russia unless they rediscover the form that propelled them to glory in Brazil in 2014 in a crunch match against Sweden on Saturday.
Joachim Loew's defending champions slumped to a 1-0 defeat against Mexico in their opening Group F match, paying the price for a calamitous first half in a performance that drew stinging criticism.
Lothar Matthaeus, the 1990 World Cup-winning captain, said he had not seen a Germany team "so weak at a big tournament for a long time" following the loss in Moscow.
The holders will likely be without defensive pillar Mats Hummels due to a neck injury, while striker Marco Reus could be handed a start after a bright 30-minute cameo off the bench against Mexico.
"Everyone is ready to fight for their lives," said forward Timo Werner, who is again set to lead the Germany attack.
With 10 World Cup goals to his name, Germany will also expect more from Thomas Mueller at his third World Cup.
"The pressure is terrifically high, but we won't win both games if we beat ourselves up internally and look for the mistakes in each other," said Mueller, with Germany set to meet South Korea in their final match.
Sweden beat the Koreans 1-0 to join Mexico at the top of the section, but a stomach bug prevented three players -- Pontus Jansson, Filip Helander and Marcus Rohden -- from initially travelling to Sochi with the rest of the squad.
Sweden are also hoping Victor Lindelof can return after sitting out the opener due to an illness of his own.
"This is really what you spend your whole career and life working towards. It is an extraordinary opportunity to be involved in a World Cup match like this," said Sweden boss Janne Andersson.
"Whether we knock out Germany is one thing, but we have a chance to qualify and that is extraordinary."
Romelu Lukaku and Belgium can effectively lock up a last-16 berth with victory over Tunisia in Moscow in Group G, ahead of a blockbuster clash with England next week.
Lukaku scored twice in a 3-0 win over debutants Panama, and Roberto Martinez is trying to finally squeeze the best out of a squad brimming with talent.
"The World Cup does not respect generations, the World Cup doesn't respect individual names, it only respects winning teams," Martinez said.
Mexico head into their showdown with South Korea after a "milestone" win over Germany, but a misstep in Rostov-on-Don would undo all that good work.
South Korea are drawing inspiration from Asian rivals Japan and Iran as they bid to avoid a premature end to their Russian adventure.
- Neymar strikes -
Brazil, one of several contenders to make a slow start in Russia, left it late before finally overcoming a plucky Costa Rica 2-0 on Friday.
Neymar won a penalty before referee Bjorn Kuipers reversed his decision after he consulted the video assistant referee, the first time a spot-kick award has been chalked off at the tournament.
Philippe Coutinho broke the deadlock in the 91st minute and Neymar volleyed in a second with virtually the last kick of the game.
Brazil must pick up at least a point against Serbia next Wednesday to be assured of progressing, with Switzerland also in a strong position in Group E after Xherdan Shaqiri's 90th-minute winner in a 2-1 victory over Serbia.
Shaqiri and Granit Xhaka, who scored Switzerland's equaliser, both celebrated their goals by making a double eagle gesture with their hands to represent the Albanian flag, with which many people in Kosovo identify.
Switzerland coach Vladimir Petkovic was unimpressed with the celebrations of the two players, who both trace their roots back to Kosovo, a former province of Serbia.
"You should never mix politics and football. It's good to be a fan and important to show respect," he said.
Argentina received a lifeline in Group D as Ahmed Musa's double sealed a 2-0 victory for Nigeria over Iceland, who saw Gylfi Sigurdsson blast a VAR-awarded penalty over the bar.
Lionel Messi and his teammates looked down and out after capitulating against Croatia, but a win over Nigeria on June 26 could send them through as runners-up.