South Koreans will be anxiously awaiting news of whether captain Son Heung-min is available when they need him most, as the Asian giants start their World Cup campaign on Thursday against a Uruguay side with a track record of deep runs in the tournament.
The Tottenham Hotspur forward sustained multiple fractures around his left eye three weeks ago and has been training in Qatar wearing a black protective mask reminiscent of swashbuckling vigilante Zorro.
Group H also includes Portugal and Ghana, meaning Son's unrelenting threat and firepower against an uncertain Uruguayan defense will be vital for South Korea to pick up some crucial early points by negating Uruguay's attacking flair.
South Korea coach Paulo Bento has imposed a team gag order on discussing Son's state of World Cup readiness, hoping to keep Uruguay's strategists in the dark.
"We should check and analyze day by day, let him come," Bento said in the run-up to Qatar.
"We have time to make the right decisions and the best decisions for all of us."
Son is eager to play, wary of the possibility of further injuries from a premature return, last week saying he was "more than willing to bear those risks".
Uruguay are once again the dark horses of the tournament, with a squad that combines a trusted old guard of players age 35 or above, with exciting young talent eager to make their mark in their first World Cup.
They includes Liverpool's record signing Darwin Nunez, who is expected to be paired up front with the ageing Luis Suarez, a key component in Uruguay's impressive march to the semi-finals in the 2010 World Cup.
Nunez at 23 is 12 years younger than Suarez and fellow forward Edinson Cavani, who play in their fourth World Cup, as does captain and most capped player Diego Godin.
Among 13 debutants will be Real Madrid's versatile midfielder Federico Valverde and Manchester United's Facundo Pellistri, who link up with Tottenham's in-form Rodrigo Bentancur in a midfield for which Uruguay's squad has plenty of depth.
Coach Diego Alonso sees the yawning age gap as a boon and believes Uruguay could even win this World Cup, as they did in 1930 and 1950.
That could be a tall order and commentators have noted frailties at the back that South Korea could exploit, particularly in the center, while there is no word yet on whether Barcelona's Ronald Araujo is available after undergoing thigh surgery.
Uruguay have reached 14 World Cups and South Korea 11, but neither has a good record in their opening match, with the Asian side losing or drawing in their last two World Cups and Uruguay unable to win their openers in six of their last seven editions.