The Houston Astros will take to the field with some new administrative personnel today when they close out a three-game series with the visiting Arizona Diamondbacks at Minute Maid Park.

Houston, which dropped Friday's opener by a 3-1 score, found itself without a manager and a pair of coaches after following the initial loss with a 12-4 defeat to the Diamondbacks in Saturday's second game.

Manager Brad Mills was informed of the decision by general manager Jeff Luhnow after the game. Mills was 171-274 since his hiring in October 2009 and becomes the fourth consecutive Astros manager to be fired mid-season, following Jimy Williams, Phil Garner and Cecil Cooper.

"I love the players, I love the effort they gave every day," Mills said. "They've been great to me and how they've gone about everything and I love our fans. The fans we have here in Houston are the best, and they've been great to me, as well, and I appreciate them an awful lot. I wish the best for the players and the fans as we move forward."

Hitting coach Mike Barnett and first base coach Bobby Meachem were also dismissed amid a stretch where the Astros have won just six times in 35 games since the All-Star break and only 12 times on the road all season.

Tony DeFrancesco was named interim manager on Sunday. DeFrancesco had been managing Houston's Triple-A affiliate, the Oklahoma City RedHawks.

The Astros start day one of the new era with Venezuelan righty Armando Galarraga, who starts for the fifth time in a Houston uniform since he was signed as a free agent in late May.

The 30-year-old got a no-decision against Pittsburgh in his first outing on July 28 and has since dropped consecutive decisions to Atlanta, Washington and the Chicago Cubs while combining to allow 15 runs in 20 1/3 innings across the four games.

He was touched for five runs on seven hits in five innings against the Cubs on Aug. 13 and will try again for his first win in the big leagues since a 5-4 win at Cincinnati while with the Diamondbacks on April 19, 2011.

He was 3-4 in eight starts with Arizona last season and is 1-0 against the Diamondbacks in two career starts.

He's opposed by right-hander Ian Kennedy, who'll try to end a two-start skid.

A 21-game winner last season, Kennedy got to 10-8 this season with a 4-2 win at Philadelphia on Aug. 3 before consecutive losses at Pittsburgh and St. Louis dropped him back to .500 at 10-10.

He allowed six runs in four innings against the Pirates on Aug. 8, then was touched for five runs in six innings against the Cardinals six days later.

Kennedy won his lone career meeting against the Astros after allowing eight hits and striking out three over 6 2/3 scoreless innings in a 1-0 win on May 4, 2010.

In Saturday's second game, Aaron Hill capped an impressive nine-run fifth inning with a three-run home run as the Diamondbacks thumped the Astros.

Chris Young smoked a solo home run among his four hits, scored twice and finished with three RBI. Ryan Wheeler clubbed his first major league long ball, while Justin Upton, Paul Goldschmidt and Stephen Drew added RBI for the Diamondbacks, who have won three straight.

Patrick Corbin (5-4) allowed four runs on seven hits with a walk and five strikeouts to pick up the win, while Houston starter Jordan Lyles (2-10) was rocked for seven runs - five earned - on eight hits and three walks over four- plus innings in defeat.

"He had a real efficient last two innings and won another game for us," Arizona manager Kirk Gibson said.

Chris Snyder ripped a two-run home run and Tyler Greene hit a solo shot for the Astros, who have lost three in a row and five of their last six.

The Diamondbacks swept the three-game series in Phoenix in July, outscoring the Astros, 33-13. Arizona won the 2011 season series, six games to one, and hasn't lost it since 2006.