The U.S. men's national team won its three group matches at the Concacaf Gold Cup, but it didn't emerge from the opening phase unscathed.
Center back Walker Zimmerman has been ruled out with a hamstring injury, which he suffered in the first half of Sunday's win over Canada. He was replaced 15 minutes into the match by Donovan Pines.
Zimmerman captained the U.S. in the last two group games and was the most experienced center back on what's generally a young and inexperienced team. Miles Robinson, James Sands and Pines are the remaining central defenders on the squad.