His family, from his relatives to his teammates and players, always has come first. And that's why the leader of the Chicago Cubs decided to step down after Sunday's game against the Atlanta Braves - he wants to spend more time with his ailing mother.
"My mom needs me home and that's where I'm going," Piniella said before one last game in the dugout.
Piniella said last month he planned to retire at the end of the season and reiterated his plans just Saturday. But he missed four games in August to be with his mom in Florida and decided this weekend his divided attention wasn't helping anyone.
"She hasn't gotten any better since I've been here," he said. "She's had a couple other complications, and rather than continue to go home, come back, it's not fair to the team, it's not fair to the players. So the best thing is just to step down and go home and take care of my mother."
The surprising announcement - made in a team handout Sunday morning after Piniella had repeatedly insisted he would finish the season - led to a memorable scene at Wrigley Field, when Piniella brought the lineup card and greeted another retiring manager who's had a great run - Bobby Cox.
And Cox empathized with his counterpart.
"It's in your blood that long, but Lou's mom is in ill health," Cox said before the game. "It's a sad day for me because I kept on thinking that Lou would be back, not here but somewhere else."
Piniella, who turns 67 on Saturday, and Cox shook hands at the plate, hugged each other and exchanged back slaps as Piniella's No. 41 was posted on the center field scoreboard.
Cox was announced to the crowd and took his cap off and waved it to the fans.
Then the public address announcer ran down Piniella's achievements as he stood at the plate, and scattered cheers of "Louuu" could be heard throughout the crowd.
After Piniella and Cox posed for a picture with the umpires, the managers hugged each other again. Piniella then headed to the dugout as the cheers got louder, took off his cap, waved it to the crowd and then began to clap for the fans.
Third base coach Mike Quade was promoted to interim manager, getting the nod over bench coach Alan Trammell, who was thought to have been a candidate to succeed Piniella next season. But general manager Jim Hendry said Trammell was not going to be considered for the job, so Quade got the nod to finish out the season.
Piniella met with his team to let them know he was leaving and it was very emotional, despite the Cubs' terribly disappointing season - two years after they had the best record in the NL.
"I wish we would've played better for him," reliever Sean Marshall said.
"You hate to see stuff like that. You hate to see a grown man kind of tear up like that, it just shows his heart for winning and his drive for baseball and his family."
Entering Sunday's game, Piniella's overall record was 1,835-1,712 (.517). He trails only Tony La Russa, Cox and Joe Torre in victories among active managers.
Piniella's record with the Cubs was 316-292. Under the mellowed skipper, Chicago won consecutive NL Central titles in 2007-08, but missed the playoffs last year and slipped back even further this season with a new owner, Tom Ricketts, in charge.
"I've enjoyed it here," Piniella said. "In four wonderful years I've made a lot of friends and had some success here, this year has been a little bit of a struggle. But, look. Family is important, it comes first."
In 18 years in the majors as a player - he had a .291 career batting average - and another 22 as a manager, Piniella made five trips to the World Series and has three championship rings. He began his professional playing career in 1962.
"It's a very tough day for him, very emotional," Hendry said of the man he hired four years ago to replace Dusty Baker. "There has been some times the last couple of months where he knew his family was possibly going to need him. He certainly didn't want to go out before the end of the year, but it's just at the point now where he need to be home with his mother and his family."
Piniella began managing in 1986 with the Yankees and lasted three years, including a stint as general manager. He managed the Reds from 1990-92, leading them to a World Series championship in his first season. He also got national attention during his time there for a clubhouse wrestling match with reliever Rob Dibble, who downplayed the incident and said "we've been family ever since."
After Cincinnati, Piniella had a long run in Seattle, where his teams won at least 90 games four times and 116 in 2001. The three-time manager of the year also spent three seasons in Tampa Bay's dugout, but he questioned his hometown team's commitment to winning at the time before the team bought out the final year of his four-year contract.
The Cubs won 97 games under Piniella in 2008, but were swept out of the playoffs for the second straight year and it's been mostly downhill since that successful run.
What Chicago fans saw for the most part was a more reserved Piniella, although he did have one meltdown with an umpire early in his first season and soon thereafter the Cubs took off and eventually overtook the Milwaukee Brewers to win the NL Central in 2007.
Piniella joined the Cubs after doing some TV work, looking for a final challenge and hoping - like so many before him - that he would be the manager to bring the Cubs a long-awaited championship. The Cubs' last World Series appearance came in 1945, their last World Series winner in 1908. It didn't happen, despite the promising first two seasons.
"It's a tough job. But, look. I mean. They're going to win here. They've got a family owned business now," Piniella said.
"The Ricketts family is going to do what they need to do to get this thing to where it can win. They're going to give it the care that it deserves. When I took this job I didn't call anybody. I came here and did the best I could for as long as I've been here. That's all you can do," he added.
With one last game to manage, Piniella said he would look back later.
"I'll have plenty of time to reflect, I will," he said.
"I've enjoyed it. It's a wonderful place to work and wonderful people to work with and for. To end a career in a place like Wrigley in a city like Chicago with these wonderful fans, I couldn't be more appreciative to the Cub organization."