The Nationals have re-signed left-hander Zach Duke to a Major League contract, according to Amanda Comak of the Washington Times (via Twitter).

Duke spent most of the 2012 season with the Nats' Triple-A affiliate in Syracuse, posting a 3.51 ERA in 26 starts for the Chiefs. When the 29-year-old got a chance to pitch out of the Nationals bullpen in the last month of the season, he was very effective, recording a 1.32 ERA in eight appearances.

The signing doesn't rule out additional pitching acquisitions for the Nationals, according to Comak, who says (via Twitter) that the club is still in the market for a fifth starter.