South Korea are sweating over the fitness of defender Kim Min-jae ahead of their second group H match against Ghana on Monday.
The Napoli star is a major doubt for the must-win game at the Education City Stadium in Al Rayyan after missing second straight day of training with a calf injury.
The South Korean officials are trying to downplay his condition, insisting it's not serious.
The 26-year-old suffered the setback during his country's gritty 0-0 draw against Uruguay in their opening match on Thursday.
It's a massive concern for the Asian giants- who are keen to have their best arsenals in top shape for the crunch tie against the African giants.
The Manchester United target could not train on Friday and skipped the session again on Saturday to spark fears of his potential unavailability.
"Kim Min-jae has some lingering pains, and he stayed back in the team hotel for treatment and rest," a national team official told reporters at Al Egla Training Site in Doha.
Kim slipped and fell while trying to chase down Uruguayan forward Darwin Nunez in the second half. Kim stayed down on the pitch in obvious pain but played the rest of the contest. He said afterward he has suffered muscle strain but he didn't think it was serious.
Kim has been enjoying a successful first season with Napoli in the top Italian league, earning the Serie A Player of the Month honor for September and the Italian Footballers' Association's Player of the Month for October. He is easily the best defender for the Taegeuk Warriors and one of the team's most valuable players.