Eleven golfers affiliated with the breakaway LIV Golf series have filed an antitrust lawsuit against the PGA Tour, challenging its suspensions and other restrictive measures used to punish those who signed on to play in the Saudi-backed LIV events.

The lawsuit, filed Wednesday in the U.S. District Court for the Northern District of California, argues that the PGA Tour is unfairly controlling players with anticompetitive restraints to protect its longstanding monopoly on professional golf.

The complaint — filed on behalf of Phil Mickelson and others — alleges that the tour had “ventured to harm” their careers and livelihoods. “The Tour’s unlawful strategy has been both harmful to the players and successful in threatening LIV Golf’s otherwise-promising launch,” it said.