Davey sending Roark to start against Marlins

PHILADELPHIA -- The Nationals have decided to start right-hander Tanner Roark on Saturday against the Marlins instead of right-hander Ross Ohlendorf, who will go back to the bullpen as a long man.

Roark has been valuable in long relief since joining the team from Triple-A Syracuse on Aug. 6, but manager Davey Johnson said he deserves a chance to be in the rotation, based on scouting reports from Minor League pitching coordinator Spin Williams.

Johnson added that Ohlendorf going back to the bullpen is not a demotion.

"This is giving Tanner Roark an opportunity to start up here in the big leagues and see how he fits," Johnson said. "He was good out of the 'pen, but he is a young starter. Spin Williams really likes him as a big league starter. So we figured we take a look at that."

Ohlendorf went 2-0 with a 3.62 ERA in five starts, but what concerned the Nationals was that his pitches would slow by at least 10 miles an hour by the time he reached the sixth inning -- at one point Johnson thought he was running out of gas. Ohlendorf last pitched on Sunday, against the Mets, going five innings and allowing four runs in a 6-5 victory.

Johnson could have had Stephen Strasburg pitch on Saturday, but hamstring issues have been bothering Strasburg for a couple of starts, though he is expected to pitch on Sunday on six days' rest.

"It's not worth the risk-reward," Johnson said of using Strasburg early.