Houston @ San Francisco preview

Last Meeting ( Jul 14, 2012 ) Houston 2, San Francisco 3

The San Francisco Giants will look for a three-game sweep of the Houston Astros after moving into first place in the NL West, a half-game ahead of the Los Angeles Dodgers. Tim Lincecum looked sharp Saturday, but it might be time to start worrying about the Giants’ bullpen. Santiago Casilla has blown four of his last six save chances, and he could be sharing the closer’s role with Jeremy Affeldt and Sergio Romo before long. If the Giants decide to trade for bullpen help, Houston closer Brett Myers and setup man Brandon Lyon are both reportedly available.

The Astros have lost 12 of their past 13 games, including 12 straight on the road. Things got even worse during Saturday’s 3-2, 12-inning loss when shortstop Jed Lowrie left in the third inning with a painful leg injury. The team will learn more about Lowrie’s status on Sunday, but it appears he’s likely headed to the disabled list. Lowrie leads all Astros regulars in on-base percentage and slugging percentage, and he’s batting .253 with 14 home runs. Brian Bixler replaced Lowrie on Saturday and went 0-for-3 with three strikeouts.

TV: 4:05 p.m. ET, FS Houston (Houston), CSNBA (San Francisco)

PITCHING MATCHUP: Astros RH Bud Norris (5-6, 4.71 ERA) vs. Giants RH Matt Cain (9-3, 2.62)

Norris is winless in his last six starts, going 0-5 with a 7.85 ERA during that span. He gave up three runs against the Giants on June 12 before leaving after 3 1/3 innings with a knee injury that landed him on the disabled list. A native of the Bay Area, Norris has 88 strikeouts over 86 innings.

Cain, who earned the win as the National League’s starting pitcher in Tuesday’s All-Star Game, threw the first perfect game in Giants history on June 13 against Houston. He’s 2-3 with a 3.83 ERA in eight career games (seven starts) against the Astros. Cain struggled a bit in his last two starts before the break, giving up eight runs over 13 1/3 innings.

WALK-OFFS

1. Astros C Jason Castro could miss his third straight game Sunday because of soreness in his right knee.

2. The Giants have won 19 of their last 26 games at AT&T Park.

3. Houston SS prospect Jonathan Villar will miss six weeks after breaking his right hand punching a door on Friday. Villar has 11 homers and 50 RBIs at Double-A Corpus Christi.