Los Angeles (27-27) at New York (26-27)

Mike Pelfrey’s days with the New York Mets could be numbered.

Pelfrey will be fighting to avoid a demotion to the minor leagues on Saturday when the Mets continue their four-game series with the Los Angeles Dodgers at Shea Stadium.

Pedro Martinez, who made just one start before landing on the DL with a left hamstring strain, is scheduled to be activated Tuesday. When he returns, Pelfrey (2-6, 5.33 ERA), who has minor league options remaining, could be sent down to make room on the roster.

Pelfrey hasn’t done much to help his cause lately, as he has lost his last six starts while earning a 6.47 ERA. He has lasted only four innings in each of his last two starts, and gave up six runs - four earned - in Monday’s 7-3 loss to Florida.

“I’d like to pitch well and avoid that,” Pelfrey told the Mets’ official team Web site of being sent down. “But I’d like to pitch well to help us win. I haven’t done that. But I’ve been sent down before, and I know I can get back.”

Pelfrey, who did flirt with a no-hitter May 15 against Washington, is hoping he can do enough to impress the Mets (26-27) in his first career appearance against the Dodgers.

“I know I can be a winning pitcher, that’s what irritates me,” he said. “If I thought I wasn’t any good, I could accept it a little easier. But I know I can be, and I can help us win.”

The Mets will be trying to bounce back after their first loss in four games, Friday’s 9-5 defeat. New York had scored 20 runs during its three-game winning streak, which came after a 1-7 drought that had some questioning whether Willie Randolph should remain the team’s manager.

Luis Castillo hit a two-run homer but left in the seventh with a strained left hip flexor after turning a difficult double play. He said he hopes to return Saturday, as does right fielder Ryan Church, who missed his 10th consecutive start with a concussion.

Russell Martin went 4-for-4 with a homer and three RBIs for the Dodgers (27-27), who ended a four-game losing streak. Los Angeles scored just 12 runs in its previous seven games and seven during its losing streak, but erupted for five in the eighth inning Friday.

“Everybody did his part in that inning. We’ve got to do it more often. It was a good win,” Martin said. “Hopefully, it gets us back on track.”

Manager Joe Torre, who won four World Series titles in his 12 seasons with the crosstown Yankees, shuffled his lineup and earned his first win in New York since signing a three-year, $13 million contract with the Dodgers in the offseason. Los Angeles lost 8-4 Thursday in his first game back in the Big Apple.

Now, Torre will hand the ball to Chad Billingsley (4-6, 3.68), who gave up two runs in six innings Monday but was charged with a 3-1 road loss to the Chicago Cubs. He had gone 4-1 in his previous five starts, allowing no more than one run in the four victories.

The second of those wins came in his first career start against the Mets on May 5, when he yielded one run in six innings of a 5-1 home victory. Billingsley also threw a scoreless inning of relief against New York on June 11 without getting a decision.