Ned Yost, the Royals' career leader in managerial victories who guided the franchise to the 2015 World Series championship, will retire after the 2019 season ends Sunday.

The Royals announced Yost's retirement on Monday morning, the day after the team hit the 100-loss mark for the second straight season. He was the first Royals manager to lead the franchise to back-to-back American League pennants and finishes with a 22-9 postseason record.

"With the development of our young players and our returning veterans, I feel and hope the worst is behind us in this rebuilding phase of our organization," Yost said in a release. "My plan all along was to get us through the rough times then turn it over to a new manager to bring us the rest of the way.

"I've thoroughly enjoyed my time here as your manager and will never forget the good and the hard times we had together as an organization and a fan base. I will never forget the fact that you fans supported us through it all. Kansas City will always have a special place in my heart, and I look forward to rooting the Royals on to their next world championship very soon."

Despite speculation that the Royals will hire former Cardinals manager Mike Matheny, who served as a Royals special adviser for player development this year, as Yost's successor, the Royals are not expected to move quickly to hire a new manager headed into an offseason of transition that includes the pending sale of the franchise.

Yost became the Royals manager in May 2010, moving from an advisory role within the organization to take over for the fired Trey Hillman after 35 games.

The Royals lost 95 games in 2010 but would improve in each of the next five seasons under Yost: 71-91 in 2011, 72-90 in 2012, 86-76 in 2013, 89-73 in 2014 and 95-67 in 2015.

The 2013 team was in contention for a playoff spot though the season's final days. In 2014, Yost led the Royals to the playoffs for the first time since the 1985 World Series championship season.

Starting with the thrilling, extra-inning AL Wild Card Game victory at home, the Royals won a MLB record eight consecutive games to start the postseason, clinching the pennant with a four-game sweep of the Baltimore Orioles at Kauffman Stadium. The Royals forced a deciding seventh game of the World Series at home but lost to the San Francisco Giants.

After the World Series title over the New York Mets in 2015, Yost went 81-81 and 80-82 the next two seasons before bottoming out at 58-104 last year. The Royals are 57-100 with five games remaining this season. He's 744-836 overall as Royals manager.