Phil Mickelson took aim at the United States Golf Association on Friday for its plan to limit the length of drivers to 46 inches.
"Word is USGA is soon rolling back driver length to 46 inches," Mickelson wrote on Twitter.
"This is PATHETIC. 1st it promotes a shorter more violent swing (injury prone,) doesn't allow for length of arc to create speed, and during our 1st golf boom in 40 years, our amateur gov body keeps trying to make it less fun."
Mickelson, who reportedly uses a 47.5-inch driver, responded to several comments under his initial tweet. He called the governing golf body 'amateurs' and said 'logic isn't their strong suit'.
He became the oldest golfer to capture a major championship after winning the PGA Championship in May, just before his 51st birthday.
He has been a major-tournament champion in three different decades.