Days after his putter swipe ignited a controversy that threatened to overshadow the U.S. Open, Phil Mickelson offered an apology.

Mickelson received a two-shot penalty for purposely hitting his ball while it was still in motion on the 13th green during the third round at Shinnecock Hills. In the eyes of the USGA, his actions fell short of a disqualification for a “serious breach” of the rules, and the 48-year-old ultimately matched his age with a T-48 finish after returning to play the final round.

Mickelson declined to speak to reporters after a Sunday 66, but Wednesday he sent a note to a select group of media members that included Golf Channel’s Tim Rosaforte in which the five-time major champ offered some contrition.

“I know this should’ve come sooner, but it’s taken me a few days to calm down. My anger and frustration got the best of me last weekend,” Mickelson wrote. “I’m embarrassed and disappointed by my actions. It was clearly not my finest moment and I’m sorry.”

Mickelson’s actions drew ire from both media members and his fellow competitors, with members of both groups implying that his actions merited disqualification. His most recent remarks seem to indicate that the decision to run up and stop his ball from tumbling back across the 13th green was more of an impulse than the calculated use of the rule book he described after the third round at Shinnecock.

“It’s certainly not meant (to show disrespect). It’s meant to take advantage of the rules as best you can,” Mickelson said Saturday. “In that situation I was just, I was just going back and forth. I’ll gladly take the two shots over continuing that display.”

Mickelson is not in the field this week at the Travelers Championship and is expected to make his next start in two weeks at The Greenbrier.