ST. LOUIS -- A managerial tenure that began with four consecutive postseason runs ended abruptly for Mike Matheny on Saturday as the Cardinals announced his dismissal following the club's 8-2 loss to the Reds. Mike Shildt, who had been serving as the club's bench coach, takes over as interim manager.

Hitting coach John Mabry and assistant hitting coach Bill Mueller were also relieved of their duties. The organization will announce replacements for both during a media conference at 11 a.m. CT on Sunday in which principal owner Bill DeWitt Jr. and president of baseball operations John Mozeliak will also offer further explanation for the timing of these changes.

Matheny, who was under contract through 2020, is the first manager dismissed by the Cardinals since Joe Torre was replaced midseason in 1995. That came before DeWitt took over as chairman and chief executive officer.

"Mike Matheny has served the St. Louis Cardinals organization with tremendous dedication and pride, and I am thankful for his service to the Cardinals over the past six and a half seasons," DeWitt Jr. said in a statement released on Saturday night. "On behalf of the entire Cardinals organization, I would like to wish Mike the very best."

An organization that, under DeWitt's leadership, has preferred to wait until the offseason before making staff changes, does so now amid reports about growing turmoil in the clubhouse and evidence of a deteriorating on-field product. With one day remaining before the All-Star break, the Cardinals are 47-46 and sit seven games back of the National League Central-leading Cubs.

The Cards are in jeopardy of missing the playoffs in three straight seasons for the first time since 1997-99.

"These decisions are never easy, but we felt that a change in leadership was necessary as the team prepares to enter into the second half of the season," Mozeliak said. "I would like to thank Mike for his exceptional commitment and devotion to the Cardinals' organization, including many fond memories of our years working together."

Before dismissing Chris Maloney from the staff last June, Mozeliak had never made an in-season coaching change.

The Cardinals are likely to wait until the offseason to begin a more exhaustive search for a replacement manager. There are some experienced managers currently without a home, including Joe Girardi, who is from central Illinois and knows Mozeliak from their time overlapping in Colorado and St. Louis.

Padres bench coach Mark McGwire might get some consideration. Mozeliak also has a longstanding relationship with Jim Riggleman, who hasn't been guaranteed the Reds' managerial position despite his role in helping the organization turn around its season. Riggleman served as the Cardinals' Minor League field coordinator from 2005-07 and he briefly served as the club's farm director.

Internal candidates could include third-base coach Jose Oquendo, who has previously expressed managerial aspirations, and Stubby Clapp, who has led Triple-A Memphis to a 149-84 record since taking over as manager last year. Pitching coach Mike Maddux has previously interviewed for managerial positions elsewhere.

Matheny had no professional managerial experience when he succeeded Tony La Russa following the Cardinals' World Series championship run in 2011, and he became the first rookie manager in baseball history to lead his club to the postseason in his first four years. But since the team's World Series run in 2013, the Cardinals have incrementally taken steps back.

They fell to the Giants in the 2014 NL Championship Series, then were booted in the NL Division Series by the Cubs in '15. And though they played meaningful games into the final week of September each of the last two years, the Cardinals failed to nab a postseason berth in either. After winning 100 games in '15, they finished with 86 and 83 wins, respectively, in '16 and '17.

Seeking to address their shortcomings, the Cardinals overhauled their roster in the offseason with the stated goal of earning a postseason spot. To this point, however, the on-field play has been ragged and inconsistent. Furthermore, a focus to clean up the fundamentals had not produced the desired results. For a second straight season, the Cards have been one of the Majors' worst in the field and on the bases.

Offensively, they ranked in the bottom half of the NL in runs scored (407) and strained to piece together rallies when not hitting home runs. Several hitters -- most notably William Fowler , Kolten Wong , Tommy Pham and Marcell Ozuna -- have not performed near expectations.

And while the Cardinals' rotation has held itself together despite injuries, the bullpen never jelled under Matheny. In his final five games as manager, Matheny watched his relievers allow 26 earned runs.

Though the organization often cited his leadership abilities as one of Matheny's best attributes, concerns about that and his relationship with players had been festering as evidence of tension in the clubhouse emerged. In recent years, some players had privately expressed frustration with what they perceived to be varying standards for veteran players and younger ones. Questions about the effectiveness of his communication and in-game management had also surfaced internally.

This will be Shildt's first opportunity to manage at the big league level after serving in that capacity in the Minors. Before joining the Major League coaching staff last summer, Shildt managed eight seasons in the Cardinals' farm system.