Phil Mickelson and his caddie of 25 years Jim "Bones" Mackay said in a stunning announcement Tuesday that they have agreed to mutually part ways. 

Mickelson and Bones have been together as a player-caddie duo since 1992. Mckay helped Lefty to 38 top 10s in majors (five victories) and the duo took 11 trips to the Ryder Cup. In a sport where many relationships only last a year or two, theirs certainly stood out.

"After an amazing 25-year run, Phil and I have mutually decided to go our separate ways," Bones said in a statement. "Player-caddie relationship don't often last that long. I will always be grateful that I was around to witness so much of Phil's career. When Phil hired me in 1992, I had one dream: To caddie in a Ryder Cup. 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."

"After 25 very rewarding and memorable years, Bones and I have mutually decided to end our player-caddie relationship," Mickelson said in a statement. "Our decision is not based on a single incident. We just feel it's the right time for a change. Bones is one of the most knowledgeable and dedicated caddies in the world. He is always prepared and has the ability to make decisions in pressure-packed situations. Bones is without a doubt one of the most thoughtful people that I have ever known. The next player to work with him will obviously be very lucky."

Just last week, Bones was at Erin Hills preparing to caddie for Mickelson should the five-time major winner be able to fly cross-country for the U.S. Open following his daughter's graduation. Mickelson wasn't able to make it, but Bones' attendance at Erin Hills shows there was nary a sign at the time that this move was coming.

There have been a few behind-the-scenes whispers about the relationship between Mickelson and Bones, but given the love affair they've clearly had with one another over the past two-plus decades, it was still difficult to see this coming.

Heck, Luke Donald once tweeted that "Phil and Bones are the best player/caddy partnership in golf. It's hard to last as long as they have together yet they have done it with ease."

Unfortunately, that is no longer the case.

Now it will be fascinating to see what happens with Bones. Their joint announcement noted that Tim Mickelson, Phil's brother, will be his caddie for now. He caddied for him one day at the WGC-Mexico Championship this year. Will Bones grab another bag? He's widely considered one of the best in the business, and it's not hard to see another top player giving him a ring. 

Bones was one of the faces of the caddie profession, and he caddied for the most popular player in the world. Their split is shocking and a huge bummer for those who have followed Lefty over the years.