Dustin Johnson of the United States, left and Martin Kymer of Germany practice in green before the first round of the inaugural LIV Golf Invitation at Centurion Club in St. Albans, England on Thursday.

Even before it started, the Saudi-backed LIV golf series reshaped the careers of several high-profile players, with golfers like Phil Mickelson and Dustin Johnson having to spend PGA tours and their relationships with some of their sponsors.

A revenge was expected from the PGA Tour - and shortly after the opening LIV tournament ended on Thursday, the PGA imposed a ban on 17 players who took part in the new series.

PGA Tour Commissioner Jay Monahan said in a letter to tour members that players would not be "suspended or otherwise eligible to participate in PGA Tour tournament games, including the Presidency Cup."

Golfers include Mickelson and Johnson, Louis Ostuigen (21), Kevin Na (34), Tailor Gooch (35) and Sergio Garcia (57).Nine of the 17 golfers turned down their PGA Tour membership.

LIV Golf is backed by Saudi Arabia's wealth, allowing top players to be enticed by the promise of cash - from eye-popping incentives to millions of prize money and guaranteed payments.

PGA Tour says defectors are motivated by money, by playing in the LIV event, 17 golfers "deliberately decided to turn their backs on the PGA Tour in violation of a regulation," Monahan wrote in his letter. Any player who follows them on a Saudi-backed tour will meet the "same fate".

The golfers "chose them for their own financial reasons," and it has been officially announced that they are now banned from the PGA Tour event, Monahan said.

Penalties for the PGA Tour do not affect major golf tournaments, such as next week's US Open. Because the majors are governed by their own governing body.

This week, the US Golf Association said they would not bar players from the US Open if they participated in the LIV event.

But LIV's relationship with Saudi Arabia's oppressive monarchy immediately provoked a strong reaction, due to the state's blatant human rights abuses.

Critics - even Mickelson himself - have noted that US intelligence has concluded that Saudi Crown Prince approved the operation to direct journalist Jamal Khashoggi to the 2018 brutal assassination

Michelson said in February after discussing why he was adopting the new golf series despite the well-known human rights violations by the Saudi regime:

But on Monday, Mickelson confirmed he would play in this week's LIV event, at the risk of PGA's rage. With the threat of a ban, Johnson and other players resigned from the PGA Tour.