USA coach Jurgen Klinsmann has admitted that the knee injury suffered by Stuart Holden during their Gold Cup final victory could be "very serious".
Holden was forced off after just 20 minutes of their 1-0 win over Panama after hurting his right knee in a collision with Alberto Quintero.
The Bolton Wanderers midfielder spent 16 months on the sidelines with cruciate and cartilage damage to the same knee in recent seasons, and Klinsmann admits that the early prognosis is worrying.
He told reporters: "We are very concerned. It looks like a very serious knee injury. But I'm not a doctor."
Holden used Twitter to reassure fans that he is confident of making a full recovery after battling back from persistent injury problems in the past.
He tweeted: "For all that know me + have supported me, I hope u know I will always prevail no matter what the outcome. Fingers crossed. Let's celebrate!"
Holden has been a Bolton player since 2010, making 37 appearances for the Trotters in all competitions.