United States and LA Galaxy midfielder Sebastian Lletget will miss up to six months with a foot injury.
Lletget, 24, suffered the injury during USA's 6-0 thrashing of Honduras in World Cup qualifying on Friday.
Initially thought to be a strain, Galaxy said on Tuesday Lletget had a Lisfranc injury. The three-time international needs surgery and is anticipated to be out for four to six months.
Atlanta United have also been dealt a blow as MLS leading goalscorer Josef Martinez was ruled out for at least a month with a quad injury.
The Venezuela forward, who already has five goals this season, suffered the injury on international duty.
The 23-year-old's move from Torino was only made permanent earlier this month.