IT STARTED as a vague thought, nagging at the back of his mind. It began to come into sharper focus the first day of the California road trip when, jogging around the warning track at Dodger Stadium before the series opener, he hurt his back.

Mike Schmidt was 39 years old, in a slump, playing for a Phillies team destined for another last-place finish.

Nobody had a clue that within a week he would stun even those closest to him by abruptly announcing his retirement.

Six days later, standing near third base at Candlestick Park in San Francisco, he was about to make one of the biggest decisions of his baseball life. It was a sun-splashed Memorial Day weekend Sunday. All he needed was an omen.

It was May 28, 1989, 20 years ago next week.

"Mentally, I had sort of been thinking about it," Schmidt recalled during a recent phone conversation. " 'Might this be the end? What other sign do I need?' I was looking for a jumping-off point."

Then, just like in the movies, it happened.

The score was tied at three in the bottom of the fourth. The Giants had runners on first and second with two outs when Robby Thompson hit a grounder right at third, the kind of play Schmidt had made countless times on his way to winning 10 Gold Gloves.

Except this time, the ball went through his legs for an error to load the bases. Mike Maddux relieved starter Ken Howell. And the next batter, Will Clark, hit a grand slam.

"And I'm thinking, 'I'm really getting nothing out of this. We're not a very good team. I'm not playing near to the level that I'm comfortable with. What do I do now?' " Schmidt said.

What he did was almost unthinkable. Three-time MVPs, future Hall of Famers don't just walk away, thousands of miles away from home, in the middle of a season, without dropping a hint or bouncing the idea off a few confidants.

But that's just what Schmidt did.

"After the game, I walked into the clubhouse and it was like I was in a fog," he said. "I showered real fast, paid the clubhouse guy and went out and sat on the bus all by myself for 30 or 40 minutes to contemplate my next move."

He called his wife, Donna, and his agent. Before the chartered plane to San Diego took off, he informed manager Nick Leyva of his decision. During the flight he made his announcement to the traveling party. There was a small news conference at Jack Murphy Stadium the next day, then a larger one at Veterans Stadium when he returned to Philadelphia.

"And that was it. I just cleaned out my locker and waited to see if I would get any phone calls," he said.

"I think the important thing at the time of my decision is that the team - and you always want to put the team first - was not a contender. Everybody understood it was a rebuilding process. We weren't going to win the division. Whether I was there or not, we were pretty much going to finish in the same place. Maybe it would be easier to rebuild without having to think about me. I was not going to be a big part of their future. Once I removed myself, the rebuilding process started working pretty quickly."

Schmidt's adjustment to life after baseball took a little longer. Today he has what he calls a "wonderful, wonderful life." It took a while to reach that level of contentment.

"In the early days of my retirement, my relationship with the team was minimal. I think that was all my doing," he said. "I wanted to leave baseball. I'd had enough of the traveling and the lifestyle. I wanted to start a new phase of my life with my wife and kids and family. I also had a yearning for warm weather and a yearning for golf. That took us to Florida.

"At the same time, nobody was saying, 'Please stay and work for us.' "

So he spent some time playing on a professional celebrity golf tour. He was inducted into the Hall of Fame. He wrote a book. He became more involved with the church. He did charitable work, including a deep-sea fishing tournament that has raised more than $1.2 million for multiple-sclerosis research over the last 10 years. He was third-base coach for Team USA in this year's World Baseball Classic. And he has been reunited with the only organization he ever played for, most visibly spending time in Clearwater as a special spring-training instructor.

Asked about regrets or remaining goals, he laughed. "I'd love to win a golf tournament sometime, although I don't know when that would be," he said.

"Get back in baseball? I don't know. I had a wonderful year in Clearwater [as manager of the Phillies' Class A Threshers farm team in 2004], but it didn't really lead to anything at the major league level.

"Is there a void when it comes to coaching or managing at the major league level? Maybe so. I don't know. I'll be 60 in September. I don't know if tackling a long-term position is what I want to do right now. I can't say I want to manage for a year or 6 months. Nobody wants a part-time coach. They want dedicated people."

What happened on Memorial Day weekend, 20 years ago next week, is a reminder that you never know for sure what's going to happen in baseball. *