San Francisco @ San Diego preview

Last Meeting ( Apr 27, 2013 ) San Francisco 7, San Diego 8

The San Francisco Giants look to snap a four-game losing streak when they face the San Diego Padres in Sunday’s series finale at Petco Park. The Padres have won three straight by one run, including Saturday’s 12-inning, 8-7 victory when they rallied from an early five-run deficit. After a dismal start, San Diego is 3-1 with Chase Headley and Carlos Quentin both in the lineup. The power hitters have had a positive impact on the entire batting order, with rookie second baseman Jedd Gyorko going 7-for-19 over the last five games.

The Giants have lost four straight for the first time since losing five in a row last July 25-30, and they made several costly errors in Saturday’s frustrating defeat. “Everybody knows we’re not playing as a team right now,” Giants second baseman Marco Scutaro told reporters after the game. “We’ve kind of been inconsistent putting defense and offense and pitching together.” Shortstop Brandon Crawford has been the exception, and he continued his strong play Saturday by hitting his career-high fifth home run. He homered four times in 143 games last season.

TV: 4:10 p.m. ET, Comcast SportsNet Bay Area, Fox Sports San Diego

PITCHING MATCHUP: Giants RH Ryan Vogelsong (1-1, 5.68 ERA) vs. Padres RH Jason Marquis (1-2, 4.63)

Vogelsong has tossed seven innings in each of his last two starts, including last Monday when he allowed four runs against the Diamondbacks. Will Venable is 6-for-10 and Everth Cabrera has two hits in 11 at-bats against Vogelsong, who has a 20-to-7 strikeout-to-walk ratio through four starts. The 35-year-old right-hander, who has allowed four home runs in his first 25 1/3 innings, went 3-1 with a 2.05 ERA in four starts against San Diego last season.

After three solid outings to start the season, Marquis allowed seven runs over 4 2/3 innings against Milwaukee last Monday. “I just don’t feel comfortable on the mound,” Marquis said after the start. “My fastball command is not where I want it to be.” The 34-year-old is 6-5 with a 2.82 ERA in 14 career starts against the Giants. Pablo Sandoval is 6-for-17 with two homers and Hunter Pence is 11-for-26 with one home run against Marquis, who went 1-1 with a 2.03 ERA in two starts against San Francisco last season.

WALK-OFFS

1. The Giants are looking to avoid their first five-game road losing streak since May 19-23, 2010.

2. San Diego’s bullpen has allowed three runs in their last 29 2/3 innings over the last 11 games.

3. Giants LHP Jeremy Affeldt (strained oblique) threw 30 pitches on Saturday and could be activated from the disabled list on Tuesday.

PREDICTION: Giants 6, Padres 3