La Russa, the third-winningest manager of all time and most assuredly a future Hall of Famer, retired fewer than three days after winning a World Series for the third time, the second time with St. Louis.
The surprising announcement was made during a Monday morning news conference at Busch Stadium.
"There isn't one [factor] that dominates [my decision]," La Russa said. "They all just come together, telling you your time is over.
"We went through the season, and I felt that this just feels like it's time to end it, and I think it's going to be great for the Cardinals to refresh what's going on here."
La Russa is one of nine managers to win the World Series three times and is the only one to win it all in three decades. He's also one of two managers, along with Billy Southworth, to win two World Series titles with the Cardinals.
La Russa said that he'd made his decision to retire in August, informing general manager John Mozeliak at that time, and had been leaning that way since even earlier in the season. He told his coaching staff and players on Sunday, following the club's World Series parade and celebration. La Russa informed players on the stage inside Busch Stadium that he wished to speak with them, and made an announcement to the club shortly after the event ended.
LARGE AND IN CHARGE
"I'm looking forward to what's ahead," La Russa said. "I'm ready to do something different."
For the time being, La Russa does not have a next job in line. He does not expect to return to the organization but indicated that he had some interest in continuing to work in baseball.
Mozeliak acknowledged that he has a preliminary list of people in mind to be the Cardinals' next manager, but he made it clear that he expects that list to change in the coming days. Mozeliak did not rule out any possibility for the next skipper, from internal candidates to managers not currently with a team to coaches or managers with other teams.
However, Monday was not about looking ahead. The Cardinals parted ways with the winningest manager in franchise history, a man who amassed 1,408 regular-season victories with them in 16 seasons. He made nine postseason appearances in St. Louis, won three pennants and wrapped up his second World Series championship with the Cards on Friday night.
"Today is about Tony," Mozeliak said. "Tomorrow is going to be about the next chapter for the St. Louis Cardinals. We've started to think about it. We've put together a search committee. And we'll begin doing our due diligence late this afternoon, and beginning tomorrow we'll hit the ground running.
"But when I think back to my time with him, he's been a leader, a mentor, a friend. And when you have somebody step away from your life that incorporates all that, it's never a great feeling."
La Russa, 67, steps down with 2,728 managerial victories, ranking behind only Connie Mack (3,731) and John McGraw (2,763). Only Mack has managed in more ballgames. The Cardinals skipper is also the only manager in Major League Baseball history to win multiple pennants in both leagues and the second to win a World Series title in each as well.
Career managerial wins
La Russa's Oakland A's won the World Series in 1989. Hall of Famer Sparky Anderson won World Series titles with Cincinnati and Detroit. The Cardinals' championship was their second in the past six seasons.
La Russa said that he did not consider continuing in order to get the 36 wins he would have needed and pass McGraw on the all-time list.
"I'm aware of the history of the game," La Russa said. "But I would not be happy with myself if the reason I came back was to move up one spot. That's not why you manage ... it's not something that motivates me. Wherever you finish, you finish."
The club and La Russa held a mutual contract option for 2012, and Mozeliak had said as recently as Sunday night that the team hoped to have its manager back. La Russa downplayed the significance of a bout with shingles during the year in his decision, insisting that it was simply time.
"We're grateful for what he's done for the Cardinals all these years," Cardinals chairman and chief executive officer Bill DeWitt Jr. said.
La Russa's managerial ranks
St. Louis -- which lost starting pitcher Adam Wainwright for the season before Spring Training and played without key players, such as Matt Holliday, Albert Pujols and National League Championship Series and World Series MVP David Freese, for significant stretches of the regular season -- climbed out of a 10 1/2-game NL Wild Card hole in late August to make the playoffs.
"In the baseball world and in Missouri, Tony La Russa was already a legendary figure before last week's World Series championship," Missouri Gov. Jay Nixon said. "But after leading the Cardinals on one of the most outstanding runs in baseball history, Tony La Russa retires as an icon. He's truly irreplaceable. On behalf of the people of Missouri, I thank Tony La Russa for everything he gave Missouri -- both on and off the field."
La Russa called the timing of his decision and the Cardinals' deficit a "coincidence."
"That's a good connection to make," La Russa said, "because of the coincidence, but it's inaccurate."
A light-hitting second baseman, mostly for the A's, over parts of six Major League seasons, La Russa began his managerial career with the Chicago White Sox in 1979. After parts of eight seasons with them, he moved to Oakland during the '86 season and won the World Series with the A's in '89, in the middle of three consecutive American League pennants.
"Tony La Russa certainly left his mark on the game of baseball," White Sox chairman Jerry Reinsdorf said. "His brilliance is his legacy. One of two managers to win a World Series in each league, six pennants, it says a lot about the man that he wasn't just going to stick around to break records."
The Cardinals hired La Russa in 1996. They finished in first place seven times and made the postseason nine times during his 16 seasons.
While he said, "I think it's better to step away for a long while," La Russa did not rule out taking another position in baseball.
"It's a little scary because I don't know if the phone's going to ring about doing something else in baseball," La Russa said. "Maybe buy a Minor League club and keep my hand in it that way."
Fun facts from the Tony La Russa era
Matthew Leach is a reporter for MLB.com. Read his blog, Obviously, You're Not a Golfer and follow him on Twitter at @MatthewHLeach. This story was not subject to the approval of Major League Baseball or its clubs.