Jozy Altidore has a hamstring injury, though the severity of that injury is yet to be confirmed. The American striker was left out of Sunderland's squad to face Crystal Palace on Saturday, which obviously puts his position in the United States squad for upcoming World Cup qualifiers in doubt. If Altidore sitting out against Palace was more than just precautionary, it's tough to see him taking the pitch on Friday, even if his injury is very minor.
Altidore has scored in five consecutive games for the United States, including three World Cup qualifiers, and would be a massive loss if he's not fit to start. The United States' forward ranks are not exactly loaded at the moment, especially given Herculez Gomez's injury.
Eddie Johnson has been in solid form for the Seattle Sounders and would be the most likely candidate to start in Altidore's absence. New USMNT striker Aron Johannsson has impressed in the Eredivise and looked dangerous in his only USMNT appearance to date, so him getting the nod isn't completely out of the question, even if it is a bit unlikely.
As for who might be called in to replace Altidore, that's anyone's guess. Chris Wondolowski was effective in Gold Cup and could get the nod, but there are plenty of solid American strikers who have performed well in MLS this season. Bobby Wood could be a dark horse for a call-up as well.