Together for 25 years and more than 600 golf tournaments, Phil Mickelson and caddie Jim “Bones” Mackay are moving on.

In a surprising email just two days after the U.S. Open that Mickelson didn’t play, they said the decision to part ways was mutual and not based on any one incident.

“We just feel it’s the right time for a change,” Mickelson said.

They were apart the last time they were together. Mickelson was home in California to attend his daughter’s high school graduation, while Mackay was at Erin Hills in Wisconsin taking notes and scouting the course just in case a weather delay were to allow Mickelson to make his tee time.

“Player-caddie relationships don’t often last that long,” Mackay said. “I will always be grateful that I was around to witness so much of Phil’s career.”

Mackay previously caddied for Larry Mize and Scott Simpson when he was hired in 1992 to work for Mickelson, who had won a PGA Tour event while at Arizona State. Their first event was a U.S. Open qualifier, and Mickelson shot rounds of 69-63.

They were together for 45 victories worldwide, including five majors, and every Presidents Cup or Ryder Cup team since 1994.

“When Phil hired me in 1992, I had one dream: to caddie in a Ryder Cup,” Mackay said. “Last year, at Hazeltine, Phil played in his 11th straight Ryder Cup. It was so cool to have a front row seat. I wish Phil nothing but the best. His game is still at an elite level, and when he wins in the future (definitely the Masters), I will be among the first to congratulate him.”

Mackay is not retiring as a caddie, though he had no immediate plans. He is coming off double knee replacement surgery during the last offseason.

Mickelson said his brother, Tim Mickelson, would caddie for him the rest of the year.

TIGER WOODS has checked into a clinic to get help dealing with prescription medication for pain and a sleep disorder, and his agent is not sure how long he will stay.

Mark Steinberg of Excel Sports Management said Tuesday he could not disclose the location of the in-patient treatment. He said pain medication at times was the only way Woods could get up and moving during the toughest days of recovery following four back surgeries.

“I’m proud of him,” Steinberg said. “He’s going to get himself right to be able to essentially lead a healthy lifestyle.”

Woods was arrested on a DUI charge in the early hours of Memorial Day when police in Jupiter, Florida, found him asleep behind the wheel of his slightly damaged car, which was parked awkwardly to the side of the road about 15 miles from his house, headed the opposite direction.

This is at least the second time that Woods has sought in-patient treatment. He was in a Mississippi clinic for 45 days in early 2010 when his personal life collapsed over multiple extramarital affairs.

Woods had his fourth knee surgery after winning the 2008 U.S. Open at Torrey Pines for his 14th major. Starting in 2013, however, his back has been the primary source of his injuries. He has had four surgeries on his back starting in the spring of 2014, the most recent fusion surgery two months ago.

THE PGA TOUR is beefing up its anti-doping policy by adding blood testing next season.

The tour also is bringing its list of banned substances in line with the World Anti-Doping Association. The revised policy takes effect in October at the start of next season.

Blood testing will allow the tour to detect any use of human growth hormone, which is on the list of banned substances but cannot be detected through urine. The tour, however, still plans to use urine samples for most of its drug testing next season.