U.S. Soccer released the full schedule for the 2016 Lamar Hunt U.S. Open Cup today, including the date that MLS clubs will enter the competition. After the third round of the competition on June 1, the winners of those 15 matches will be joined by the 17 MLS clubs in the fourth round on June 15.
MLS clubs will at least have an idea of their fourth round opponents whenever the third round matches are announced, as 15 of the clubs will be paired with a specific third round matchup. The two remaining MLS clubs will play against each other to finish off the fourth round fixture list.
In the 2015 Open Cup, Seattle Sounders FC were selected for the MLS-on-MLS fixture with Cascadia rivals Portland Timbers, a memorable match with a forgettable scoreline that the Sounders will hope to put far behind them when the fourth round fixture list is released.
S2, like all other USL teams owned and operated by a MLS team, will not be allowed to compete in this year's tournament. The Sounders U23 team, however, will compete as they are owned by a separate group. They are one of 19 PDL teams to qualify and will start in the first round on May 19.