In a text Wednesday morning, Phil Mickelson apologized for his rules breach on Saturday at the U.S. Open.

GOLF.com’s Alan Shipnuck, who was among the reporters to receive the text, reported its contents. “I know this should’ve come sooner, but it’s taken me a few days to calm down,” Mickelson wrote. “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.”

The incident in question came on the 13th hole Saturday, when Mickelson, having just hit a putt that was going to roll off the green, chased after his ball and hit it back toward the hole while it was still moving. Under Rule 14-5 he was assessed a two-stroke penalty for the move, although some suggested he should have been disqualified.