What happened to the Padres?

As the Dodgers and San Diego Padres open a three-game series Friday at Dodger Stadium, the cynical preview is this: Pitchers’ duel!

The Padres have not scored in 14 innings. The Dodgers have not scored in 31 innings.

The Dodgers, at least, are in first place in the National League West. The Padres, built with the expectation of challenging the Dodgers and San Francisco Giants, are tied with the Arizona Diamondbacks for third place.

The Padres are 20-22. What’s up?

-- San Diego has had a relatively rough schedule so far. The Dodgers and Padres have almost identical records within the NL West -- 17-13 for the Dodgers, 15-12 for the Padres -- but San Diego has played 13 games outside the division against teams with winning records. The Dodgers have played none.

-- The Padres’ new and improved outfield has delivered mixed results. Justin Upton has 11 home runs, the most of any player in the NL West. Wil Myers is on the disabled list, and before his injury the Padres had moved him from center field to first base, in the absence of the injured Yonder Alonso.

Matt Kemp, who once played in 399 consecutive games for the Dodgers, has played in all 42 of the Padres’ games. But his hot April (.326 with a .835 OPS) has dissolved into a bitterly cold May (.176 with a .408 OPS). He has one home run in 166 at-bats this season, and his overall .645 OPS ranks 10th among NL right fielders.

-- Defensively, the Padres’ outfield has been the worst in the majors. The defense cannot help but compound the issues of the Padres’ pitching staff. The Padres have given up the most unearned runs of any team in the NL West.

James Shields, the imported ace, is 5-0 with a 3.74 earned-run average; he leads the league in strikeouts and home runs allowed. Tyson Ross leads the league in walks. Andrew Cashner leads the league in losses.

The bullpen, for so long a San Diego staple, has the next-to-worst ERA in the NL. Craig Kimbrel, touted as the best closer in baseball when the Padres acquired him on the eve of the regular season, has converted 10 of 11 saves but has a 5.74 ERA and has been scored upon in seven of his last 11 appearances.

-- And, given their respective home parks, this might be the most amazing statistic in baseball this season: the Padres have given up more runs than the Colorado Rockies.