Aston Villa earned a 1-0 victory over Chicago Fire but Gabriel Agbonlahor and Darren Bent face a period on the sidelines due to injury.
Agbonlahor scored Villa's winner in the first half of their pre-season friendly in Chicago on Saturday night before being forced off with an ankle complaint.
The problem was initially thought to be serious but the club soon moved to play down the 25-year-old forward's setback.
Villa posted on their official Twitter feed: "Gabby Agbonlahor injury not as bad as first feared. Out for two weeks."
Agbonlahor is the second England international striker to struggle during the club's pre-season tour of North America with record signing Bent also out with a slight thigh strain.
Paul Lambert's side, who beat the Philadelphia Union on Wednesday, now head to Portland for a game on Tuesday.