Sunderland striker Jozy Altidore missed out on his team's 3-1 loss to Crystal Palace with a hamstring injury, the club's official Twitter account confirmed. The injury leaves the forward's status for the USA's upcoming World Cup qualifiers very much in doubt.
The 23-year-old scored his first goal for Sunderland in the Capital One Cup midweek, helping his team to a 4-2 comeback win over MK Dons.
Altidore has been in red-hot form for the USA, scoring in five consecutive matches, including a hat trick in the team's friendly against Bosnia-Herzegovina on Aug. 14.
The U.S. travels south to face Costa Rica on Friday, before heading to Columbus four days later to play Mexico in a much-anticipated showdown. The Yanks are currently on top of the Hexagonal with a 4-1-1 record through six of 10 games.
With Altidore's status in doubt, the onus could fall on one of the other four listed forwards on the team's roster: Clint Dempsey, Landon Donovan, Eddie Johnson and Aron Johannsson.