Arsenal midfielder Gedion Zelalem will be out between six and nine months after tearing his cruciate ligament while on international duty.
The 20-year-old featured for the USA’s Under-20 World Cup opener but he left the pitch after only 34 minutes.
He joined the Gunners in 2013 before being loaned out to Rangers in the summer of 2015 and Dutch second-tier side VVV-Venlo during last summer's transfer window.
The youngster was expected to meet with Arsenal to decide where he would be playing his football next season.
He will undergo knee surgery in the coming days and will need at least six months to recover.
"For Gedion, this was his second U-20 World Cup, so his experience was invaluable for us," U.S. Coach Tab Ramos told the media.
"His passing ability is second to none in this tournament, and we'll miss that. He was running the team from his position."
