The American has not played since controversial comments about the Saudi Arabian-funded events were published by his biographer in FebruaryPhil Mickelson refused to deny that he has been banned by the PGA Tour on the eve of playing in the world's most lucrative golf event.
The Centurion Club, near London, is this week hosting a Saudi-funded $25m invitational tournament, the first of eight worth a cumulative $255m (£200m).
Six-time major winner Mickelson, who in February made "reckless" comments about Saudi Arabia's regime, is ending a four-month self-imposed exile to play.
"I'm learning lessons," said Mickelson.
"I would be speaking on a PGA Tour matter publicly, which I choose not to do at this time."
He added: "I've enjoyed my time on the PGA Tour and I have strong opinions on what could and should be done a lot better, but I will make an effort to keep those conversations behind closed doors.
"I don't want to give up [my lifetime membership of the PGA Tour] but I don't know what's going to happen."
The PGA Tour has threatened bans for any of its members that play in the LIV Golf events. It is expected that any sanctions to be meted out will only be made public after the players tee off at 14:15 BST on Thursday.
The 51-year-old American also refused to confirm reports that he is being paid $200m to play in the LIV Golf events, but also hinted it could be true.
He said: "Contract agreements should remain private. Doesn't seem to be the case, but it should be."
Before this week, Mickelson last played in the Asian Tour's Saudi International in King Abdullah Economic City, along with many other PGA Tour players.
Saudi Arabia's Public Investment Fund (PIF), which was the title sponsor of that event, is bankrolling the LIV Golf Invitational Series to the tune of $255m (£200m) in prize money. It is fronted by former world number one Greg Norman, who intends to turn it into a 14-event league by 2024, backed by a further £1.6bn of PIF money.
However, two-time major champion Norman, 67, was criticised last month when he said "we've all made mistakes" after being asked about Saudi Arabia's human rights record while promoting the series.
Mickelson lost multiple sponsors and saw his reputation tarnished after he criticised the Saudi regime, yet sought to use involvement with the series to gain leverage over the PGA Tour.
He subsequently missed the Masters for the first time in 28 years as well as last month's US PGA Championship, where he would have been defending champion.
However, he said he intends to play in next week's US Open and the United States Golf Association, which runs the major, has said it will not stop those competing in the LIV event from playing at Brookline, Massachusetts.
'Is there a danger you could be seen as Saudi stooge?' - Mickelson faces media at LIV Golf eventEarlier this week, Mickelson, who has won 45 events on the PGA Tour since joining in 1992, denied suggestions his involvement with the LIV series is due to financial difficulties caused by gambling losses.
And he said on Wednesday that this "opportunity gives me more balance on and off the golf course".
He added that it was "made clear I had the option" to play in the US PGA Championship three weeks ago but chose not to because "I wasn't ready to play".
But he feels the time is now right to return because the format of LIV's combined individual and team events are "exciting".
"I needed more balance on and off the golf course and this gives me the opportunity to have that balance," he said. "I understand people may disagree with me but this is the right decision for me."
Mickelson was asked if he had any qualms about playing in the LIV Golf event given where the funding is coming from and the Amnesty International accusations of 'sportswashing', to which he replied: "I don't condone the human rights violations."
Referring to the murder of Washington Post reporter Jamal Khashoggi inside the Saudi consulate in Istanbul in 2018, he added: "I'm aware of Jamal Khashoggi and I think it's terrible.
"I have also seen the good that the game of golf has done throughout history and I believe LIV Golf is going to do a lot of good for the game as well."
How will the LIV Golf series run?
The $25m (£20m) purse on offer this week is the most lucrative ever played for in one event, with $4m going to the winner of the 48-man event.
This initial invitational series will feature six more tournaments of this nature - four in the United States, one in Thailand and one in Saudi Arabia - each having the same $25m prize fund, meaning every leg of the series is more lucrative than the richest tournament on the PGA Tour.
The three-day 54-hole strokeplay events will feature a team and individual competition, with 12 captains selecting three players in a draft-style format. Each day, the teams of four will tee off at the same time on different holes in what is termed a 'shotgun start'.
Each event's individual winner will take home $4m - by way of comparison, the PGA Tour's flagship event, the Players Championship, earned Cameron Smith $3.6m for his victory in March, while Collin Morikawa won $2m for his Open Championship victory in 2021.
The eighth and final event, at Trump National Doral in Miami in October, will be a four-day $50m 'Team Championship' matchplay knockout tournament featuring 12 teams. The winning team will receive $16m, with each of the four players earning a 25% cut.
