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07/21/09 1:22 AM ET

Mets playing waiting game with Sheffield

New York (44-48) at Washington (26-66), 7:05 p.m. ET

WASHINGTON -- The ailing Mets can barely wait to reinsert a no-longer-ailing Gary Sheffield into the lineup.

Manager Jerry Manuel had been hopeful that Sheffield, who has been out of the lineup since leaving Friday's game with right hamstring cramps, could be back in the Mets' starting lineup as early as Tuesday, against the Nationals.

But after Monday's game, Manuel indicated that the Mets will likely have to wait some more.

"We'll check him again [on Tuesday]," Manuel said. "He was available as a pinch-hitter [on Monday]. We'll see how he feels. We will probably not start him. With the lefty [John Lannan starting for Washington], it will probably be [Fernando] Tatis in left field."

Tatis is 4-10 in his career against Lannan, and Sheffield is 2-6 with a home run. Sheffield is the only Met who has more than 10 home runs this season.

Without Sheffield providing a power source in the middle of the batting order, the Mets scored six combined runs in three games entering Monday's series opener at Washington. In that game they scored six runs -- just the third game this month where they reached that total.

Sheffield did not feel pain when hitting before Monday's game, but the 40-year-old outfielder felt tenderness when he tested his hamstring with running exercises.

Sheffield said that he had a similar issue with cramping during Spring Training last year.

"Nobody knew what it was," Sheffield said. "I was cramping up every time I tried to run. My electrolytes were off, they were saying. It lasted for like a week."

Manuel expressed the possibility of holding Sheffield out through the team's scheduled off-day on Thursday if his health doesn't improve.

Pitching matchup
NYM: LHP Oliver Perez (2-2, 7.99 ERA)
Given to dramatic swings in performance, Perez produced a middle-of-the-road start in his most recent appearance, on Thursday in Atlanta. He allowed three runs, nine baserunners -- four on walks -- and bases-empty home runs to two successive batters. Two of the critical hits were produced by left-handed hitters. Those figures might have resulted in a victory, but the Mets scored three, so they resulted in Perez's third no-decision in seven starts. Now he faces an opponent that has troubled him over the years. Since the beginning of the 2006 season, he has started eight games against the Nationals, winning twice and losing four times, producing a 7.53 ERA and allowing 72 baserunners in 40 2/3 innings. Austin Kearns has a .345 average and four home runs in 29 career at-bats against Perez.

WSH: LHP John Lannan (6-7, 3.64 ERA)
Lannan continues to give the Nationals one good performance after another, but a lack of run support has led to his sub-.500 record. He put up a quality start last Thursday against the Cubs, hurling 6 2/3 innings and giving up three runs (two earned), but the Nationals could only spot him one run. He has allowed three earned runs in 15 of his past 17 starts.

Jeff Francoeur has a team-high six hits in 12 at-bats against Lannan. On Monday, Francoeur popped a home run in the top of the ninth inning. Seven minutes later, Braves outfielder Ryan Church, whom Francoeur was traded for earlier this month, hit a pinch-hit homer. ... On Monday, Livan Hernandez won for the first time in seven starts. He has given up just three earned runs in 23 innings pitched against the Nationals.

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On the Internet
 Gameday Audio
•  Gameday
•  Official game notes

On television

On radio
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Up next
• Wednesday: Mets (Mike Pelfrey, 7-5, 5.07) at Nationals (Craig Stammen, 2-5, 4.46), 7:05 p.m. ET
• Thursday: Off-day
• Friday: Mets (Johan Santana, 11-7, 2.92) at Astros (Mike Hampton, 5-7, 4.63), 8:05 p.m. ET

Mark Selig is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.