The club formerly known as the Wizards will host the MLS select against a yet-to-be-named foreign club in July this year and Garber was thrilled to announce the event late last week alongside SKC president Robb Heineman.
"This market has just been so incredibly exciting for all of us at Major League Soccer - and really for soccer fans throughout the United States and North America," Garber said.
"This has been one of the great, great success stories for our sport. We're very proud of what's taken place here."
Garber went on to add that MLS had promised to send a high-profile event the way of the Kansas City when they were building the soccer-specific stadium which opened in June 2011.
"You build it, and we'll come," he added. "Now, we're announcing that we are. We had a commitment to them that we would work to find a special event - not any one in particular. We didn't have this date in mind. It just turned out that this was the timing that made sense for them and made sense for the league."