The Seattle Sounders are officially back in the U.S. Open Cup after a new format for the tournament was announced on Wednesday. The 2027 version will feature 96 teams, including all 27 eligible MLS teams. The rest of the field will be made up of 32 amateur teams and a collection of USL Championship, USL League One and independent MLS Next Pro teams.
The first round of the tournament is scheduled to take place in April, pitting most of the lower-division professional teams against amateur opponents. The 32 winners will then advance to the Round of 64, where the 27 MLS teams will enter along with five seeded USL Championship teams. That round will be played July 8–11, just before the start of the first-ever summer-to-spring MLS campaign, with the Round of 32 scheduled for Sept. 14–15. Leagues Cup is scheduled to return in mid-August.
One key to bringing all MLS teams back into the fold was apparently a willingness to expand U.S. Open Cup rosters from 18 to 20 players and allow unlimited call-ups from MLS Next Pro and academy teams. In other words, it’s entirely possible that a team like the Sounders could field a roster very similar to the one the Tacoma Defiance used in the 2025 tournament.
Those caveats aside, this will mark the first time since 2023 and just the second time since 2019 that the Sounders have fielded a team in the tournament they’ve won four times. In 2024, MLS began limiting the number of teams that participated in the U.S. Open Cup, citing fixture congestion.
