At 83-67, the Brewers have 12 games to rebound.
Milwaukee came into this month with a 5 1/2-game lead in the wild card, but since has lost 11 of 14 - including a four-game sweep completed by the Phillies over the weekend.
"[Yost] didn't have all the answers for what is going on the last two weeks and I'm not sure I have all the answers," general manager Doug Melvin said during a news conference at a hotel in Chicago. "I'm not sure this is the right one, either."
Melvin met with principal owner Mark Attanasio yesterday morning and the decision to fire Yost was made. Melvin acknowledged it was an unprecedented move but one that "shows we're serious about winning."
"We just felt a managerial change at least gives us a chance to see if we can turn it around," he added.
The Brewers were idle yesterday and will begin a three-game series against the Central-leading Chicago Cubs at Wrigley Field tonight.
During the rejiggered 1981 season, the Montreal Expos fired future Hall of Fame manager Dick Williams in early September. The Expos went 16-11 under Jim Fanning to win the second-half title and make the playoffs.
Sveum immediately hired Hall of Famer Robin Yount, his former teammate, to be his bench coach and said Garth Iorg will coach third base. "Something obviously went wrong the last two weeks," Sveum said.
In 2007, the Brewers held an 8 1/2-game division lead in late June but slid to 83-79 and missed the playoffs.
