By Mark Lamport-Stokes LOS ANGELES (Reuters) - Throughout his Hall of Fame career, Phil Mickelson has richly entertained fans with his swashbuckling, sometimes high-risk, approach to golf and his dazzling skills around the green. Nicknamed "Phil the Thrill" by many, the American left-hander is known for being a gambler, both on and off the course, and has long been one of the biggest drawcards in the game. Thrust under a non-sporting spotlight - news late on Friday of a federal probe into possible insider trading involving him, billionaire investor Carl Icahn and Las Vegas gambler William Walters - Mickelson was the picture of composed. He put out a statement through his manager saying he had done nothing wrong and was cooperating with authorities. Then, after Saturday's third round play at the Memorial Tournament in Dublin, Ohio, he politely took questions from reporters, but declined to be drawn out. Such composure marks his game preparations. Always exciting to watch, Mickelson has established a reputation for becoming one of the most meticulous practitioners in the game with his build-up to the big events, plotting out his strategy and club selection in careful fashion. While capable of driving up television ratings almost single-handedly when in contention for one of the sport's bigger events, Mickelson is also admired for being a committed family man and a generous donor to various charities. He brought his unique skills to the PGA Tour in spectacular style by winning the 1991 Northern Telecom Open as an amateur, a feat which has not been matched since, and has gone on to clinch a further 41 titles, including five major championships. Despite the probe into possible insider trading, for the moment he will likely be given the benefit of any doubt by golf fans because of his public status as a 'people's champion'. A source confirming the federal probe said Mickelson, Icahn and Walters have not been accused of any wrongdoing. Icahn said his firm always followed the law and Walters did not respond to requests for comment. READINESS TO CONNECT The ever-smiling Mickelson signs more autographs than any of his peers and, whether his fans are young or old, he loves them all. He relishes the high-fives and the congenial hand-slapping with the spectators as he moves past the galleries on his journey from green to tee. He loves the calls of "Go Phil" that erupt whenever he mounts a charge and, Tiger Woods' fans apart, there has been no louder noise at major championships over the past decade than the cheers for Mickelson when he moves into contention. Eleven years ago, when the European Tour’s Scottish Open was held at Loch Lomond, Mickelson showed his ability to connect instantly with young golf fans. An 8-year-old boy on his first outing to a golf tournament was startled to be given a ball by Mickelson after just five minutes of watching the action at the par-three eighth hole. Mickelson, who had made a habit of playing in the event as part of his British Open build-up, tossed the ball the boy's way with a friendly grin as he walked off the green. The young fan had never heard of the American but nine months later he was told by his father that Mickelson, after a 14-year wait, had finally made his major breakthrough by winning the 2004 Masters. The boy still has that ball today. Mickelson, 43, says he has a golf hero in mind when he makes the connections with fans. "When I was growing up playing the game and when I first came out on tour, the person that I tried to emulate the most was Arnold Palmer," said Mickelson, inducted into the World Golf Hall of Fame in 2012. He recalled watching Palmer during the 1994 U.S. Open at Oakmont, emerging from the volunteer tent after signing autographs for about 1,000 people. "People were thanking him profusely and his comment to them was: 'You guys spent hours on end helping out with this event ... yet you don't have a chance to go out and see any golf at all. I wanted to come here and let you know how much we appreciate it'. "So I've used him as a role model. I'm not able to do it always but I do my best to show the same respect that he does." Mickelson, who clinched his fifth major title at last year’s British Open with one of the all-time great closing rounds, may be popular with fans but on occasion he has appeared completely out of touch with how most people live. 'DUMB' COMMENTS Early last year, he made what he later described as "dumb" public comments while venting his feelings about soaring tax rates for millionaires in his native California. He had said he was considering making drastic changes after being "targeted both federally and by the state," and hinted he might even leave the state. "It was insensitive to talk about it publicly to those people who are not able to find a job, that are struggling paycheck to paycheck," Mickelson said later in apology. Since he began hitting golf balls aged just 18 months, Mickelson has piled up career earnings of more than $73 million and considerably more via corporate endorsements and his golf course design company. According to Forbes, he is seventh on its list of the world's highest-paid athletes, second only to Woods among golfers. In the 12 months to July 2013, his total earnings were $48.7 million, Forbes said. Once regarded by some of his peers as somewhat aloof, Mickelson has become a father figure to many of the younger players on the PGA Tour and has mentored fellow Americans such as Keegan Bradley, the 2011 PGA Championship winner. “I love Phil. Everything he's done for me is great. He's a very competitive guy, but he's very helpful at the same time. I thank him for his advice and help," said Bradley, who has become accustomed to Mickelson’s side-bets during tournament practice rounds when they often partner up in team play. Mickelson is known for his love of gambling. He says he has reined in the habit, but he is still well remembered for the $560,000 he earned with some friends on a preseason bet that the Baltimore Ravens would win the 2001 Super Bowl. (Editing by Frances Kerry)