Ryan Vogelsong should probably look at his last start at Coors Field rather than his first five if he is looking for comfort entering his latest trip to Denver.

San Francisco's right-hander hasn't enjoyed much success at the hitter's paradise, but the Giants need him to snap their own skid in Thursday night's series opener against the Colorado Rockies.

San Francisco (69-64) has squandered opportunity to make up ground in the NL wild card, dropping five straight to remain 6 1/2 games back of a Chicago team that's lost six of eight.

More from FoxSports

Wednesday's 2-1 loss to the Los Angeles Dodgers was the Giants' third straight by one run and knocked them 6 1/2 back of the NL West leaders, their largest deficit this season.

The Giants have 11 runs during the five-game slide, and manager Bruce Bochy was ejected for the second consecutive game Wednesday.

''Stranger things have happened,'' Bochy said. ''Trust me. There's a lot of baseball left.''

After falling flat to the top team in the division, the Giants have three straight series against teams at the bottom - last-place Colorado (54-78), Arizona and San Diego.

Vogelsong (9-10, 4.19 ERA) holds a 3-3 record and 7.14 ERA in six starts at Coors Field, but he enjoyed his best start there May 22, picking up his first win at the park since 2012 with six scoreless innings in an 11-8 victory. He surrendered two hits while walking three and striking out five.

Vogelsong moved his ERA below 4.00 for the first time all season after a 2-0 win over St. Louis on Aug. 18, but he lost his last two starts. The 38-year-old combined to give up seven runs and 14 hits in eight innings between a 5-2 defeat at Pittsburgh on Aug. 23 and a 6-0 loss to the Cardinals on Saturday.

Carlos Gonzalez hit a grand slam and two-run homer during Colorado's 9-4 win Wednesday over the Diamondbacks, but he's 1 for 17 against Vogelsong. Wilin Rosario was one of four September callups for the Rockies, and he is 5 for 14 with three home runs when facing Vogelsong.

Gonzalez had a career-high seven RBIs on Wednesday and is hitting .319 with 23 home runs and 52 RBIs in his last 49 games.

''He's been pretty locked in for a while now,'' manager Walt Weiss said. ''He can change the game at any time. ... He's one of those guys, one of the freaks in the league that can do something to wow you on any given night.''

The Rockies will send Chris Rusin (4-7, 4.94) to the mound as they try to win for the fourth time in six games.

Rusin had good numbers last month outside of a career-high 11 runs given up in two innings during a 14-9 loss to the New York Mets on Aug. 22 - tied with Arizona's David Buchanan and Kansas City's Jeremy Guthrie for the most runs allowed in a start this season.

Rusin rebounded to allow three runs in six innings during Saturday's 4-3 loss in Pittsburgh, his third quality start of the month.

The left-hander is 1-5 with a 5.05 ERA in his last 11 starts, the only victory coming from his first career complete game in a 5-0 win over San Diego on Aug. 16.

Colorado first baseman Justin Morneau has been out since May with concussion symptoms but rejoined the team this week. He has not been activated, and Weiss said Morneau has not been cleared to play despite hitting .500 on a five-game rehab assignment with Double-A New Britain.