Locke puts scoreless streak on the line vs. Strasburg, Nats

Left-hander Jeff Locke tries to stretch his unbeaten string to five starts Saturday afternoon when the Pittsburgh Pirates go up against a struggling Stephen Strasburg and the Washington Nationals at PNC Park.

Locke tossed a career-best seven scoreless innings in his last start in the Pirates' 9-0 whitewash of the St. Louis Cardinals on Sunday. He brings a 13- inning scoreless streak into today after blanking the Phillies in six frames on April 23.

Locke has won each of his last three decisions since a 6-2 road loss to the Dodgers in his initial start of the season April 7.

Pittsburgh's Minor League Pitcher of the Year in 2012, Locke has never faced the Nationals.

Strasburg is going in the opposite direction of Locke with an 0-4 stretch over his last five starts since a season-opening victory against Miami. The right- hander didn't get a decision in a six-inning performance at Atlanta Monday.

Nationals manager Davey Johnson said after the game that Strasburg had some tightness in his forearm.

Strasburg faced the Pirates twice in his career, winning both starts while pitching to a 2.08 ERA.

Last night, Andrew McCutchen continued his torrid run against the Nationals with three more hits and A.J. Burnett spun seven innings of one-run ball in Pittsburgh's 3-1 victory.

McCutchen hit his 11th career home run against Washington, and has gone an impressive 41-for-90 in 24 career games versus the club. Jordy Mercer contributed a two-run homer to help the Pirates to their second straight win.

Burnett (3-2), unbeaten in his last five starts, struck out nine and allowed just five hits.

"We were very efficient tonight," Burnett said. "We mix some change-ups, which we normally don't throw, and we got a few more strikeouts on fastballs."

Jason Grilli worked around a one-out single in the ninth to notch his 12th save of the season.

Washington fell for the fourth time in six games, with Ross Detwiler (1-3) suffering a third straight losing decision. The lefty gave up three runs on six hits and two walks over five-plus frames.

Adam LaRoche went 2-for-3 and Danny Espinosa plated the Nats' only run with an RBI single in the setback.

"We are striking out more than we should," Nationals manager Davey Johnson said. "We're trying to make too much happen."

The Pirates won three of five contests against the Nationals last season.