A number of fellow professionals felt Mickelson should have been disqualified for a serious breach of etiquette, but the left-hander was given a two-shot penalty for breaking rule 14-5 and eventually finished joint 48th.

Mickelson told critics of his actions to “toughen up” after claiming he was simply using the rules to his advantage, but a few days later sent a message to a handful of American journalists offering his apologies.

The 48-year-old was also penalised for tapping down some long grass in front of a tee during last week’s Greenbrier Classic and, speaking after an opening round of 70 in the ASI Scottish Open, said: “I’ve had a rough month. I haven’t been my best. So I’m working at trying to fix that.

I made a big mistake (at the US Open) and I wish I could take it back, but I can’t. 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 than some of the times where I have not been involved in the decisions and had to deal with that.

“You have to be accountable for yourself. I do a lot of dumb stuff, right.

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.”