World number seven Rory McIlroy feels there has been a "massive over-reaction" to Phil Mickelson's conduct at last week's US Open.
The American left-hander was criticised by some fellow professionals after badly overhitting a putt on the 13th green at Shinnecock Hills and, seeing where it was heading, ran around and struck it again.
Some called for the five-time major winner to be disqualified but breach of rule 14-5 (playing a moving ball) was invoked which instead incurred a two-shot penalty.
Mickelson belatedly apologised on Wednesday, saying he was "embarrassed and disappointed" by his actions.
McIlroy, who missed the cut and did not see the incident in Saturday's third round, was surprised by the backlash.
"I was practising when it happened. When I came back in, I saw what happened. Honestly, I laughed," the Ulsterman told a press conference ahead of his participation in the Travelers Championship in Connecticut.
"I felt there was a massive overreaction to it. Knowing Phil, he knew what he was doing.
"A player that's been in that head space at that tournament, I can see it happening to people.
"It's a tournament that Phil has come so close to winning over the past few years.
"He's probably seen what's happened over the past few years at that tournament, and it's frustrated him because it's the only one that he hasn't won, plus it's probably becoming the hardest one to win for anyone because it is a bit of a lottery at times.
"You know, I don't know if I'd go to the lengths that he went to make a statement like that, but I thought there was a massive over-reaction to it."
Phil Mickelson has had enough of hole 13 at the #USOpen pic.twitter.com/MKeYBHSLDJ
— FOX Sports Radio (@FoxSportsRadio) June 16, 2018
