Carlos Osorio/AP

Ross Ohlendorf took the mound for the first time since experiencing a tired arm last week, throwing a 21-pitch bullpen session on Wednesday afternoon at Nationals Park. Ohlendorf tossed only 11 pitches in his last appearance on July 31, his normally mid-90s fastball topping out at an alarming 85 mph. That was because he hadn’t yet recovered from his previous appearance, a 114-pitch start on July 26, his highest pitch total since 2009.

Ohlendorf later landed on the 15-day disabled list with right shoulder inflammation. He played catch on Tuesday and reported feeling improvement each day. On Wednesday, he said he threw at full force and “felt fine.” If coaches sign off on Ohlendorf’s progress and bullpen session, Manager Davey Johnson said the right-hander would then begin a rehab assignment at a nearby minor league affiliate on Saturday.

None of the local minor league teams, however, are in town on Saturday. Class A Potomac will return home on Sunday. Class AAA Syracuse is at home on Saturday, but that’s the farthest trip.

The Nationals hope to stretch Ohlendorf to five innings in a rehab start before he can return. Ohlendorf is eligible to come off the disabled list on Aug. 16.

“We’ll see how he does,” Johnson said. “See how he’s feeling and make that determination. Maybe he just goes three innings and has to come back and do five. Maybe he feels good enough and goes further and can come back earlier.”

Ohlendorf has pitched well since joining the Nationals as a hybrid long reliever and spot starter, posting a 1.85 ERA over 34 innings. Right-handed Tanner Roark was called up on Tuesday to fill Ohlendorf’s role in the meantime. If he returns in time, Ohlendorf is a candidate to slide into the starting rotation to take the place of rookie right-hander Taylor Jordan, who has about four more starts before he is shut down in his first full season back from Tommy John surgery.