Manny Acta has been fired as manager of the Washington Nationals, he told ESPNdeportes.com's Enrique Rojas on Sunday.
Bench coach Jim Riggleman will be named the Nationals' new manager at an 11:30 a.m. ET news conference at Nationals Park, according to the Washington Times.
Riggleman has managed the Padres, Cubs and Mariners.
Mike Rizzo, the Nationals' acting GM, confirmed Acta's firing Monday morning in an e-mail to The Associated Press.
The Nationals were blanked by the Houston Astros on Sunday 5-0 to go into the All-Star break with the worst record in the league at 26-61.
"I thank the Nationals for giving me this opportunity and I'm sorry that things didn't work out as expected. It's normal for the manager to pay the price when the team is not doing well," Acta said.
In three seasons at the Washington helm, Acta posted a 158-252 record. His best season came in his first when the Nats finished 73-89. Washington was on pace to win only 48 games this season.
Before getting the Nationals job, Acta was the third base coach for the New York Mets.
Acta was the third manager in the major leagues to be let go this season. Colorado's Clint Hurdle and Arizona's Bob Melvin were previously fired.
From the outset of spring training in February, Acta called the current team the most talented he's had, but significant problems in the bullpen, an untested starting rotation and the worst defense in the majors were part of a series of miscues in 2009.
The Nationals started 0-7 and never came close to approaching .500. When the team was hitting well, the pitching was a mess, and the team kept shuffling its bullpen with little change. Once the pitching became serviceable, the hitters suddenly became less productive.
This was Acta's first major league managerial job, and he always preached patience and emphasized the importance of keeping an even keel -- so much so that some wondered whether he needed to be a bit less willing to publicly abide his players' mistakes.
From the outset, working for a franchise he knew was undertaking a rebuilding process, Acta repeatedly said he would rather be an optimist than a realist, refusing to acknowledge that his team wasn't ready to be competitive.
In 2007, Acta's first season as Frank Robinson's replacement, Washington finished fourth in the NL East but a two-win improvement over 2006 and better than was expected. Acta even received votes for NL Manager of the Year.
But the team took a step backward in 2008, going 59-102 for a .366 winning percentage, the worst record in the major leagues. And there was even more regression this season -- not only are the Nationals still the worst team in baseball, but their .299 winning percentage is far lower than any other team.
The loss at Houston on Sunday was Washington's seventh in 10 games. The Nationals rank last in the NL with a 5.21 ERA and they have committed the most errors in the majors (82).
When Acta was hired in November 2006, he was 37, and no manager in the majors was younger. He was coming off two seasons as the New York Mets' third-base coach, and before that, Acta held the same job under Robinson from 2002-04, when the Nationals were still the Montreal Expos.
Acta had managed eight seasons in the minors and five in the Dominican Winter League, and he led the Dominican Republic to the semifinals at the 2006 World Baseball Classic.
When the Nationals introduced Acta as their new manager, president Stan Kasten gushed, "I knew within 30 minutes that this could be the next manager, that he had the right stuff," and then-general manager Jim Bowden brought up Jim Leyland's name, saying Acta was "going to be very special."
Acta's staff had undergone a complete overhaul already, with every coach other than pitching coach Randy St. Claire fired at the end of last season -- and St. Claire was dismissed at the beginning of June.
Acta's firing is only the latest example of the constant upheaval and instability surrounding the Nationals since Kasten and local developer Ted Lerner took over the club -- a sale that was supposed to finally bring a semblance of normalcy to the franchise.
Instead, there is now uncertainty on the bench to go along with Rizzo, who took over day-to-day GM duties shortly after Bowden resigned during spring training. Rizzo still does not have the full title.
Information from The Associated Press was used in this report.