Mattingly and the front office mutually agreed to part on Thursday as the team that bounced the Dodgers from the postseason, the New York Mets, prepared to represent the National League in the 2015 World Series.
The fact the Dodgers aren't there -- and haven't been since 1988 -- was a factor in the team's decision to move on from Mattingly, who survived only one year under the new hierarchy headed by Dodgers president of baseball operations Andrew Friedman.
According to ESPN, Mattingly was offered a contract extension last week. He has one year remaining on his existing deal. However, Mattingly turned down the new deal, per the report. Friedman said the Dodgers never officially offered Mattingly an extension.
"I can't sit here and say I'm just bubbling over," Mattingly said. "There are a lot of emotions that go into this, a lot of discussion, a lot of talk, but it gets back around to the same thing as we kept talking and going over it. We all came to the same conclusion. This is best for both parties."
Mattingly was hired in 2011 to replace Joe Torre. He led the Dodgers to three straight playoff appearances, but the team's total payroll over those seasons was $800 million, and expectations were extremely high.
The Dodgers lost in the first round of the playoffs in 2014 and 2015.
After the season ended with the NLDS loss to the Mets, Mattingly met with Friedman, general manager Farhan Zaidi and senior vice president of baseball operations Josh Byrnes for several days. Mattingly told the team executives that he was frustrated with the expectations, and Friedman and Zaidi were reluctant to extend the contract because of Mattingly's feelings about the job.
"It was a conversation," Zaidi said. "It was an organic dialogue that just led to this point -- Donnie feeling like maybe he needed a change, us feeling like taking the organization forward, if that was his state of mind, maybe it was a good time for us to make a change.
"There's always going to be a desire to label this: Was he let go? Did he resign? Understanding that, and, frankly, I've had my own level of cynicism when you hear of people mutually parting ways. But we can sit up here with all sincerity and say that's how it came about."
Mattingly acknowledged that the season wore on him but that it was no different than in past years. He said he's open to another managerial opportunity but isn't sure one will come around in 2016.
A year ago, the Dodgers' failure was almost identical and the front office was overhauled as a result. There are likely to be even more significant changes this winter as Friedman continues to implement his vision.
After being eliminated by the Mets, first baseman Adrian Gonzalez was asked if he had confidence the same group of Dodgers could finally get over the hump in 2016.
"If this is the exact same team next year, yeah," he said. "But I doubt it's going to be the exact same team."
The Dodgers won just one playoff series in those three postseasons under Mattingly's leadership (the 2013 National League Division Series against the Atlanta Braves).
The Dodgers' shortcomings in 2015 -- a rotation that dropped off severely behind Clayton Kershaw and Zack Greinke, a thin bullpen and an offense that ran hot and cold - were not necessarily Mattingly's fault.
Yet, the Friedman-led front office showed no hesitation to move players either and that figures to happen again this offseason.
Most prominently, Greinke can exercise an opt-out clause in his contract and become a free agent. Greinke, a NL Cy Young Award candidate, would be forfeiting the final three years and $71 million of his deal with the Dodgers. On the free agent market, however, he would almost certainly be able to double the total amount.
The Dodgers would have a large void to fill in an already thin starting rotation if Greinke leaves.
Changes are also likely in the infield where veteran second baseman Howie Kendrick and shortstop Jimmy Rollins will be free agents but young shortstop Corey Seager is poised to step in after an impressive showing in September and second baseman Jose Peraza was acquired from the Braves.
"It's going to be a long offseason, figuring out personal stuff and team stuff," outfielder Andre Ethier acknowledged.