Being shut out in their last two games, the defending World Series champions are struggling in a big way offensively. The San Francisco Giants will try to break out of their slump tonight when they face Houston rookie Jordan Lyles.

Coming off a 6-0 loss last night to the team with the worst record in the majors and a 1-0 final at Atlanta on Thursday, the Giants are sorely in need of a change at the plate. With losses in 15 of their last 21 games, the Giants are averaging less than three runs per game during this stretch while the offense is hitting just .233 (164-for-703), including .165 (23-for-139) with runners in scoring position.

"We're not hitting, and it's hard to score runs when you're not getting into scoring position," cried Giants manager Bruce Bochy after last night's game.

Playing the Astros would seem to be the perfect opportunity for the Giants to gain ground in the NL West standings. They are 2 1/2 games behind first- place Arizona. Six of San Francisco's next eight games, including today's tilt, are against the Astros.

On the positive side for the Giants, they'll see a pitcher tonight who has fallen on hard times in his first major league season. The 20-year-old Lyles has given up seven runs in each of his last two contests, road losses to the Dodgers and Diamondbacks. The right-hander, who had his contract purchased from Triple-A Oklahoma City on May 31, has given up 19 hits over 10 1/3 innings, covering his last two appearances. This will be his first game vs. San Francisco.

Madison Bumgarner hopes to right the ship for the Giants tonight. The 22-year- old southpaw is coming off a no-decision against the Braves on Monday when he allowed eight hits and two runs over seven frames. Prior to that he threw seven shutout frames in a victory over Pittsburgh. He has never faced the Astros.

Last night, J.B. Shuck drove in a pair of runs and Wandy Rodriguez posted eight scoreless innings for the Astros. Carlos Corporan collected three hits, scored twice and knocked in a run for the Astros, who have won three in a row. Brian Bogusevic homered and scored twice.

"We're playing more energetic on the field and it's starting to show," Shuck said. "We've got some younger guys. Hopefully we can keep doing this, get some wins the rest of this month and next month."

Rodriguez (9-9) scattered five hits and walked two, but fanned eight and added a two-run single for the victory. It was a stellar performance despite a report in a Houston newspaper which cited sources that said Rodriguez, fellow starter Brett Myers and shortstop Clint Barmes had been placed on waivers.

Ryan Vogelsong (10-3) allowed four hits and five runs -- only two earned -- over seven full frames in defeat as the Giants lost for the fourth time in five games.

Houston was 2-7 vs. the Giants last season, losing the first seven contests before winning the final two.