Updated, 7:30 p.m.

The Nationals traded veteran Jason Marquis, tonight’s starting pitcher, to the Arizona Diamondbacks, a person with knowledge of the deal confirmed. Yunesky Maya will take Marquis’s place against the Mets tonight.

In return, the Nationals received Class A shortstop Zachary Walters. The Nationals and Diamondbacks did not exchange any cash in the deal, meaning Arizona will assume the roughly $2.3 million remaining on the two-year, $15 million contract Marquis signed before the 2010 season.

Trading Marquis will clear room in the Nationals’ rotation for either Tom Milone or Brad Peacock, two of the Nationals’ top pitching prospects, to join the rotation.

Check back for more details.