Bolton Wanderers have confirmed Stuart Holden suffered a torn anterior cruciate in his right knee during the United States' Gold Cup final win over Panama on Sunday.
Holden, who was working his way back from a serious knee injury sustained in 2011, is set for another lengthy spell on the sidelines, although it is unclear whether he will miss the entirety of next season.
The 28-year-old limped off the field following a challenge in the first-half of his country's 1-0 win and appeared aggrieved as he was consoled on the sidelines by his team-mates.
Head of sports performance at Bolton, Mark Leather, said it is too early to estimate a comeback date for Holden.
"We've got the scans and the results will be analysed by our specialists," he told Bolton's official website. "We can then put an action plan in place over the next week to ten days when the initial swelling reduces."
Bolton revealed the news on their official Twitter account.
Holden will now consult with both the club's and the national side's medical staff to formulate a treatment plan. #BWFC— Official BWFC (@OfficialBWFC) July 29, 2013
Holden also took to social media to thank his fans for their support and appeared buoyant despite the latest setback to his career.