Earlier this month, FC Dallas lost its semifinal series against Mexico's Pachuca, while the Vancouver Whitecaps were eliminated by Liga MX champ Tigres in the other semifinal.
The 2016-17 winner will be crowned next week; Tigres and Pachuca tied 1-1 on Tuesday in the first match of this year's two-leg, total goals finale.
But even though a Mexican team has won the competition every year since the expanded league format began in 2008, Garber sees reason for optimism for MLS squads.
"I looked at this year's Champions League, and I walked away disappointed that Dallas, in particular, didn't go through," Garber told ESPNFC. "But I was empowered by how well they played. We're getting closer."