The US Open Cup, the country's oldest and most prestigious domestic football competition dating back to 1913, is being highlighted as a source of the "jeopardy" and knockout drama that new MLS commissioner Larry Berg says he wants to build on following the buzz generated by this summer's World Cup, which the US co-hosted. Unlike America's closed, franchise-based professional leagues, the Open Cup is open to amateur and professional teams from across the country, offering underdog stories and passionate supporter cultures, but it has struggled with declining participation from top-flight clubs even as interest in the sport grows.

The competition reached a high point in 2023 when a record 71 eligible professional teams entered and Lionel Messi was set to take part, but MLS then announced it would withdraw its clubs entirely, prompting a backlash and only a partial compromise. For the 2025 edition, just 16 of MLS's 27 US-based teams took part, and in 2026 the second-tier USL Championship sent only 17 of its then 24 clubs, partly due to the expanded calendar caused by the World Cup. Despite this, the tournament has produced notable stories, such as amateur side El Farolito (founded from a San Francisco burrito bar) and second-tier Sacramento Republic's run to the 2022 final, and there is hope for a return to fuller, more merit-based professional participation.