Phil Mickeson is “embarrassed and disappointed” by his actions after deliberately hitting a moving ball at last week’s US Open to prevent it rolling off the green.

The five-time major winner was four over par for the day on Saturday when he badly over-hit a putt on the 13th green and, seeing where it was headed, he ran around a struck it again, a breach of rule 14-5 which incurs a two-shot penalty.

A number of fellow professionals felt Mickelson should have been disqualified or withdrawn himself but he took his place in the field for the final round, eventually finishing joint 48th, 15 shots behind champion Brooks Koepka.

However, Mickelson has sent a message to a select group of the United States golf media offering his apologies.

“I know this should’ve come sooner, but it’s taken me a few days to calm down,” it reportedly said.

“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.”

Former US PGA champion Steve Elkington was among those who called for Mickelson to be disqualified and accused him of “trying to embarrass the USGA”.

Asked why Rule 1-2, which covers a ball being “influenced or deflected” and can lead to disqualification for a “serious breach” was not invoked instead, John Bodenhamer, the USGA’s senior managing director of championships and governance, said: “Phil didn’t purposely deflect or stop the ball, which is talked about in the reference under Rule 14-5. He played a moving ball.”

USGA chief executive Mike Davis later revealed that Mickelson had telephoned him to clarify whether or not he should have been disqualified.

Davis said: “Phil really did want to understand how the rule operates because he didn’t want to… frankly, as he said to me, he goes, ‘Mike, I don’t want to play in this championship if I should have been disqualified’.

“That’s where we clarified that, ‘Phil, you actually made a stroke at a moving ball, and so we have to apply that rule (14-5)’.

“That’s different than if he had deliberately just stopped the ball or whacked it in another direction or something like that. So it’s just, it’s us applying the rules.”

Jordan Spieth, in a Wednesday teleconference to talk about the defence of his Open Championship title at Carnoustie next month, said it was disappointing Koepka successfully defending his title had been overshadowed.

“I think it is a shame that the main focus hasn’t been Brooks Koepka winning back-to-back titles, from what I’ve seen or heard,” he said.

“It has been on the golf course, players complaining, Phil – you never really want that because it is such a difficult thing to win a major.

“You always want it to be about the person who won.”