In February, Mickelson took time out from golf after showing support for the planned Saudi-backed LIV Tour and drawing criticism for careless statements about Saudi Arabia and the PGA Tour.
He then did not play a single competition until June when he started playing on the LIV tour and thus was no longer welcome on the US tour.
What no one knew was that since March he was suspended from the USA tour, for, among other things, trying to recruit players for the LIV tour.
"Great damages"
In June, Mickelson wanted to have the opportunity to also play on the US tour, but got the nod.
His suspension was instead extended to March 31 of next year, according to the lawsuit, a suspension that was extended by another year later that summer.
"Mr. Mickelson's illegal two-year suspension from the PGA Tour has caused him great professional injury, both financially and commercially," the lawsuit states.
"The tour's illegal suspension means that Mr. Mickelson is denied the opportunity to play in tournaments for which he is eligible," it said.
Not sanctioned
In addition to Mickelson, American compatriot Bryson DeChambeau is one of the more famous of the eleven players taking the PGA Tour to court.
Players who switched to the Saudi-funded tour say the PGA Tour has no right to bar them from tournaments for which they are eligible.
The PGA Tour, for its part, maintains that it has the right to kick out players who play in tournaments or on tours that are not sanctioned by the PGA Tour.
Clip: 60 seconds: The heavily criticized LIV tour
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Several stars have left the PGA for LIV Photo: Bildbyrån