In a statement released Wednesday by his representatives, Mickelson admits he should have apologised sooner.

"My anger and frustration got the best of me last weekend," the five-time major winner's statement read.

"I'm embarrassed and disappointed by my actions. It was clearly not my finest moment and I'm sorry."

Mickelson was struggling in the third round when he reached the 13th green. His putt slid past the hole and was headed down and likely off the green when he trotted toward the ball and hit it back and off the hole.

He then two-putted, was assessed a two-shot penalty for a 10 on the hole and was allowed to complete his round, shooting 81.

Mickelson cited strategy for his actions Saturday, saying he knew there was a two-stroke penalty but it was better than having to play from off the green.