The USL is set for a milestone vote on the adoption of a promotion and relegation system in its lower-division men’s soccer structure, sources briefed on the plans tell The Athletic. The sources, who were granted anonymity because they were not authorized to publicly discuss the vote before it takes place, are optimistic the vote will be passed, but it is not considered a certainty.

Owners will vote on whether to proceed toward the new competitive structure at the USL’s board of governors meetings, set to take place Aug. 9-10 in Colorado Springs, Colo. If enacted, the USL would be the first open professional league system in modern U.S. soccer history.

The vote will not be on a specific and finalized framework for promotion and relegation, the sources said. Rather, the topic up for a vote will confirm whether ownership at the leagues’ clubs has enough collective interest to merit further work toward implementing an open system among the USL’s professional competitions.

A USL spokesperson declined to comment when reached by The Athletic.

The upcoming vote culminates work that publicly began in earnest at the USL’s 2021 mid-year meetings, when the organization formally proposed working toward incorporating promotion and relegation between its second-division Championship and third-division League One.