The five-time major winner will be making his 15th appearance in the event, having claimed the title in a play-off at Castle Stuart before winning the Open Championship at Muirfield a week later.
“When I won the Scottish Open in 2013 I said at the time that I had proved to myself that I could win on the links, and it has gone down as a special win for me for a lot of reasons,” said Mickelson.
“It’s a tournament that I’ve enjoyed playing in for a number of years, and to take what I learned that week at Castle Stuart and use it to help get my hands on the Claret Jug after one of the best rounds of my career, was really a fantastic experience.”
Mickelson finished joint-31st at Gullane in 2015 behind compatriot Rickie Fowler, who is also set to be in a stellar field for the Rolex Series event on 12-15 July.
“I don’t think there is a better way to get ready for a major championship than playing the week before and getting into contention and coming out on top just gives me more confidence,” he added.
“I can’t wait to get back to Gullane and play in front of the Scottish crowds again. I enjoyed the experience back in 2015 and being so close to Muirfield makes it feel a bit like a homecoming.”
Confirmation of Mickelson being added to the Gullane line up comes hot on the heels of Masters champion Patrick Reed and European No 1 Tommy Fleetwood both commiting to the event.
The trio join Fowler, world No 3 Justin Rose, 2016 Open champion Henrik Stenson, American ace Matt Kuchar and Japan’s Hideki Matsuyama in a stellar field.
Mickelson stunned the golfing world last weekend when he deliberately hit a moving ball to stop it from rolling off the green in the third round of the US Open at Shinnecock Hills.
That incurred a two-shot penalty under Rule 14-5 when many felt Mickelson should have either been disqualified or decided to withdraw under Rule 1-2.
He then stirred widespread anger within the game by raising his arms in mock celebration after holing a putt on the same green in the last round.
On Wednesday, the 48-year-old issued an apology, admitting he is “embarrassed and disappointed” by his actions in the season’s second major.
“I know this should’ve come sooner, but it’s taken me a few days to calm down,” he said in a message issued to a select group of US golf writers.
“My anger and frustration got the best of me last weekend. I’m embarrassed and disappointed by my actions. It was clearly not my finest moment and I’m sorry.”
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