WASHINGTON, Aug 7 - The Arizona Diamondbacks strengthened their starting pitching for the stretch drive by acquiring right-hander Livan Hernandez from the Washington Nationals on Monday.

In exchange the Diamondbacks shipped two minor league pitchers to the Nationals -- right-hander Garrett Mock and left-hander Matt Chico.

A two-time All-Star, Hernandez, 31, was 9-8 with a 5.34 ERA in 24 starts for the Nationals in 2006.

The 6-foot-2, 220-pound pitcher has a 119-112 career record with the Florida Marlins, San Francisco Giants and the Montreal Expos before the franchise moved to Washington.

The Diamondbacks are 56-55 this season and sit just one game back in the National League Wild Card chase and two behind the San Diego Padres in the NL West.

Hernandez was also attractive to Arizona because of his three years of post-season experience with a 5-2 record.

Mock was 4-8 with a 4.95 ERA for Class AA Tennessee of the Southern League, while Chico was 7-2 with a 2.22 ERA for the same club.

"We feel this deal gave us two pitchers that have a chance to be in our starting rotation sometime in 2008 if not 2009," Nationals general manager Jim Bowden told a conference call.