The U.S. Open announced the preliminary entry list for the second year of its revamped mixed doubles tournament on Monday, and it features stars up and down the lineup, including seven top 10 men’s singles players and eight top 10 women’s singles players. There is just one problem: There aren’t enough spots for everyone to play.

Twenty-nine teams have put their names on the list, but only 16 will play in the main draw on Tuesday, Aug. 25, and Wednesday, Aug. 26, at the Billie Jean King National Tennis Center in Flushing, N.Y. Six of those will automatically make it based on the combined singles rankings of the two players. Eight more will be chosen as wild cards by the USTA. Finally, two more teams will earn a main draw spot by advancing through the eight-team qualifying draw played on Monday, Aug. 24—the qualifying field will feature six direct entries and two wild cards.

Only two teams are locks to get into the main draw by their combined rankings: Aryna Sabalenka (No. 1) and Novak Djokovic (No. 5), with a combined ranking of six, and Elena Rybakina (No. 2) and Taylor Fritz (No. 8), with a combined ranking of 10.

Seven more teams are currently bunched together with combined rankings between 21 and 29, from Mirra Andreeva (No. 5) and Andrey Rublev (No. 16) to Amanda Anisimova (No. 10) and Learner Tien (No. 19). Whether those teams directly qualify will largely depend on those players’ performances at the Canada Open this week and next, which could move them up or down in the rankings.