Forward Kruse was withdrawn after 70 minutes of Saturday's final in Sydney, which Australia went on to win 2-1 after extra-time.
And the 26-year-old could now miss the rest of the Bundesliga season, with an initial diagnosis suggesting he has sustained a major injury.
"In Saturday’s Asian Cup Final against South Korea, won 2-1 by the Socceroos, the 26-year-old suffered serious ligament damage in his left ankle," read a statement from Leverkusen regarding Kruse's condition.
"A full diagnosis of the injury is expected on Monday.
"The striker will undergo a thorough medical examination in Australia. That will decide what happens next and whether the Kruse returns to Leverkusen or is treated back home in Australia first."
Kruse started five of Australia's six games at the Asian Cup and scored in the group-stage victory over Oman.
However, he has made only four substitute appearances for his club this term.
