LOS ANGELES — The expansion Los Angeles Football Club has sold out of season-ticket packages for its inaugural season in its new downtown stadium.

LAFC announced the sellout of 17,500 full-season memberships Wednesday, four days before the team makes its MLS regular-season debut Sunday at Seattle.

The franchise’s $350 million Banc of California Stadium is still being completed ahead of LAFC’s home debut on April 29, but the team has already sold as many season tickets as it will allow in the 22,000-seat arena.

Fans can still buy single-game tickets in the North End supporters’ section and other spots around the field.

LAFC is MLS’ 23rd franchise. The club is attracting significant attention throughout Los Angeles’ revitalized downtown, where it is building the city’s first new open-air stadium in more than 30 years.