Colorado @ San Francisco preview

Last Meeting ( Sep 12, 2012 ) San Francisco 8, Colorado 3

The San Francisco Giants begin a 10-game homestand against the Colorado Rockies with the National League West title in sight. The Giants lead the division by 7 1/2 games with 16 to play, and their magic number stands at nine after the Dodgers lost in extra innings Sunday. Giants center fielder Angel Pagan left Sunday’s game against Arizona in the sixth inning because of lower back stiffness, but he’s expected to be available for Monday’s series opener. San Francisco would love to clinch the division at home, but it won’t be easy. The Giants have lost 12 of their past 20 home games and haven’t won a homestand of longer than three games since late June.

The Rockies have lost 10 of their last 13 games, including a 12-11 defeat Sunday at San Diego. Colorado continues to use a four-man rotation, but that will change next season. According to assistant general manager Bill Geivett, the team will go back to using a traditional five-man rotation in 2013. The move will likely increase the Rockies’ chances of attracting a top free agent. While the Rockies look toward next year, the Giants are thinking about their postseason roster. Outfielder Justin Christian isn’t making a strong case to stick around after going hitless in his last 24 at-bats. Starting pitcher Ryan Vogelsong has struggled mightily in his last seven starts, but he’ll surely make the roster, perhaps as a long reliever.

TV: 10:15 p.m. ET, ROOT (Colorado), CSNBA (San Francisco)

PITCHING MATCHUP: Rockies RHP Jhoulys Chacin (2-5, 4.86 ERA) vs. Giants LH Madison Bumgarner (14-10, 3.32)

Chacin is set to make his second straight start against the Giants after allowing four runs over four innings on Tuesday. In nine career appearances (eight starts) against San Francisco, Chacin is 3-4 with a 3.78 ERA. He’s looking for his first win against the Giants in his last four starts.

Bumgarner has struggled in his last four turns, going 0-3 with a 7.29 ERA. He matched his career high by allowing 11 hits while yielding five runs in just 4 1/3 innings last Tuesday at Colorado. Bumgarner has gone 4-3 with a 2.48 ERA in 10 career starts against the Rockies, and he’s 2-0 with a 3.57 ERA in three starts this season.

WALK-OFFS

1. The Rockies are hopeful that LHP Jorge De La Rosa (Tommy John surgery) will start at least once in the final 17 games.

2. Giants LF Gregor Blanco will likely miss the series with a sore left shoulder.

3. Rockies INF Josh Rutledge snapped an 0-for-24 slump on Sunday with an eighth-inning grand slam.