San Francisco @ Colorado preview

Last Meeting ( May 15, 2012 ) Colorado 5, San Francisco 4

The San Francisco Giants have lost seven of their last eight games, so maybe a trip to Denver to face the lowly Colorado Rockies for a three-game series beginning Friday will be just what they need. Prior to their slide, the Giants led the Los Angeles Dodgers by 2 1/2 games and the Arizona Diamondbacks by six in the National League West. Those leads have slipped to one-half game and two games. It has been a season to forget for the Rockies, who have the second-worst record in the majors (38-65) while their ERA of 5.36 is last by more than half a run compared to Minnesota and Houston’s 4.82.

Colorado’s Jonathan Sanchez will face his former team for the first time since being traded to Kansas City for Melky Cabrera in November. Sanchez, who was acquired by the Rockies on July 20, is 1-8 with an 8.32 ERA overall in 2012. He will oppose San Francisco’s Ryan Vogelsong, who has recorded 16 straight quality starts and leads the majors with a 2.22 ERA. A bright spot for the Rockies is rookie Josh Rutledge, who has homered in four straight games.

TV: 8:40 p.m. ET, CS Bay Area (San Francisco), Root Sports (Colorado)

PITCHING MATCHUP: Giants RH Ryan Vogelsong (8-5, 2.22 ERA) vs. Rockies LH Jonathan Sanchez (0-2, 11.88)

Despite his microscopic ERA, Vogelsong is just 2-3 in his last seven starts. He allowed two runs (one earned) in the Giants’ 4-0 loss to the Los Angeles Dodgers. Vogelsong is 4-0 with a 1.70 ERA in 10 games (five starts) against Colorado, including a 1-0 mark with a 4.15 ERA in five games (one start) at Coors Field. He allowed one run in seven innings and didn’t receive a decision in the Giants’ 3-2 victory over the Rockies on May 14. Colorado’s roster is hitting .159 against Vogelsong.

Sanchez has allowed at least four runs in eight of his last nine starts and five or more in six of those outings. Command has also been issue as he has walked 48 and struck out 42 in 56 2/3 innings during that span. Sanchez’s only win came in his first start of the season, a 7-3 victory at the Los Angeles Angels on April 8. San Francisco batters expected to be in Friday’s starting lineup are 11-for-38 against him with Cabrera 2-for-5 with a double and Ryan Theriot 4-for-12 with a home run and two RBIs.

WALK-OFFS

1. The Giants are 25th in the majors in runs scored and averaged 2.9 runs during their just-concluded 3-7 homestand.

2. San Francisco C Buster Posey is batting .438 with four homers, seven doubles and 19 RBIs in 64 at-bats since the All-Star break.

3. The Rockies snapped a five-game losing streak – and a seven-game home skid – with an 8-2 victory over St. Louis on Thursday. They are 5-13 since the All-Star break.