(UPDATED) Battered by injury after their grueling, 10-game trek through San Francisco, Los Angeles and Boston, the Mets hope the lowly Nationals can provide a tonic tonight when John Maine takes the hill in the opener of a three-game set at Citi Field. Maine started slow coming off shoulder surgery but is on a roll lately, winning three of his past four decisions while recording a 3.00 ERA in that span.

Maine also owns the Nationals. He comes in tonight 6-2 with a 4.04 ERA in 10 career starts against Washington, including a sterling 3-0 mark with a 1.53 ERA in three starts last season.

Maine will be opposed by Long Island native John Lannan, a left-hander sporting a 1-2 record and 5.50 ERA in five career starts against the Mets.

As far as the lineup, the Mets won’t have Jose Reyes or Ryan Church again tonight but Carlos Beltran feels healthy enough to start in center field and Ramon Martinez is strong enough to fill in again for Reyes at shortstop.

Here is the 23-20 Mets’ order for the 7:10 p.m. game:

Angel Pagan RF

Luis Castillo 2B

Carlos Beltran CF

Gary Sheffield LF

David Wright 3B

Fernando Tatis 1B

Omir Santos C

Ramon Martinez SS

John Maine RHP (3-3, 4.53)

Maine’s numbers against the Nationals’ hitters

The 13-30 Nationals will counter with:

Cristian Guzman SS

Nick Johnson 1B

Ryan Zimmerman 3B

Adam Dunn LF

Austin Kearns RF

Willie Harris CF

Anderson Hernandez 2B

Wil Nieves C

John Lannan LHP (2-3, 3.63)

Lannan’s numbers against the Mets’ hitters