SAN DIEGO — The Mets’ long-discussed plan to put Bobby Parnell in the rotation becomes reality here tonight when the hard-throwing right hander makes his big-league starting debut against the Padres at Petco Park.

Parnell has been serviceable in relief as a rookie this season, compiling a 2-3 record and 3.74 ERA in 54 games mostly in a seventh- and eighth-inning role. He was last a starter in 2008 at Double-A Binghamton, going 10-6 with a 4.30 ERA.

Parnell will square off against Mat Latos in the third game of this four-game series. The righty is 3-1 with a 2.66 ERA for the Padres this season. Here is the 51-58 Mets’ order for the 10:05 p.m. game:

Angel Pagan CF

Alex Cora SS

David Wright 3B

Daniel Murphy 1B

Jeff Francoeur RF

Cory Sullivan LF

Fernando Tatis 2B

Brian Schneider C

Bobby Parnell RHP (2-3, 3.74)