Phil Mickelson conceded he does “a lot of dumb stuff” after he opened with a 70 to lie seven shots off the pace in the Aberdeen Standard Investments Scottish Open at Gullane.

As Graeme McDowell's hopes of winning one of three spots in The Open faded when he shot a one-under 69 to lie a shot outside the projected cut mark, Mickelson confessed his US Open meltdown was a huge error of judgement.

"I made a big mistake and I wish I could take it back, but I can’t," said Mickelson, who as also penalised for tapping down some long grass in front of a tee during the Greenbrier Classic last week. 

"There’s not much I can do about it now other than just try to act a little better.

“The thing about this is throughout my career, 25 years, there have been a lot of times where I have had to be accountable for decisions I did not make. 

"And the reason why this has actually been easier is it was my own fault. The backlash is my own fault. So it’s much easier to deal with. I do a lot of dumb stuff."

He added: “I have these moments where I’m like in a cloud, if you will, I’m not really sure what I’m doing or I’m just kind of going through the motions and not really aware at the moment, and I’ve done that a bunch in my career.

“At the time I was pretty angry. The way I show anger is not the traditionally accepted way of, you know, throwing clubs and berating the fans and marshals. 

"I tend to be a little more passive aggressive in my actions, and that was kind of what I was doing.”

Big-hitting American Luke List made nine birdies in a seven-under 63 to lead by a shot from compatriot Rickie Fowler, England's Robert Rock and Lee Westwood, Spain's Scott Fernandez and Sweden's Jens Dantorp.

Paul Dunne slipped from the top 10 to 29th after he double-bogeyed the 18th and signed for a 67 while Pádraig Harrington bogeyed the 16th and 18th on his way to a three-over 73.

Darren Clarke had an identical finish for a one-over 71.

On the Challenge Tour, Derry's Ruaidhri McGee was tied for seventh, three shots behind Spain's Mario Galiano and Sweden's Sebastian Soderberg,  after opening with a four-under 67 in the Italian Challenge in Sardinia.

Michael Hoey and Gavin Moynihan were tied 19th after 68s at Is Molas Resort as Ballymena's Dermot McElroy and The Island's Paul McBride shot one-under 70s to sit on the cut line.

Ardglass' Cormac Sharvin (71), West Waterford's Gary Hurley (73) and Mount Juliet's Stephen Grant (75) have work to do to make the weekend.

On the PGA Tour, Seamus Power made his lone bogey of the day at the 18th as he opened with a three-under-par 68 in the John Deere Classic at TPC Deer Run in Illinois.

He was six shots behind Steve Wheatcroft, who shot a nine-under-par 62 to lead the race for one spot in The Open at Carnoustie for the leading non-exempt player in the top-five.

Defending champion Bryson DeChambeau retired with a right shoulder injury but still plans to head to Carnoustie hoping to tee it up in the Open.

On the Symetra Tour, Stephanie Meadow is three shots off the lead after opening with a two-under 69 in the Donald Ross Classic at French Lick in Indiana.

Leona Maguire is tied 71st after a two over 73 with Lisa Maguire 139th after a 79.