WASHINGTON -- Nationals right-hander Shawn Hill had his first rehab assignment on Tuesday and pitched five shutout innings for Class-A Potomac, which blanked Myrtle Beach, 2-0.

Hill, on the disabled list due to a sore right forearm, threw 67 pitches, 45 of which went for strikes. His fastball was clocked at 90 to 91 mph. At one point during the game, Hill retired 10 consecutive batters.

Hill is hoping to pitch his first Major League game of the season against the Braves on Sunday. He said on Monday that the sharp pain in his forearm has subsided but he feels some tightness in the forearm.

Manager Manny Acta said if Hill is activated, Washington will not carry six starters. The current starting staff -- Odalis Perez, Jason Bergmann, Matt Chico, John Lannan and Tim Redding -- has pitched adequately, so the Nationals might have to make a tough decision on one of the five.

Injured outfielder Wily Mo Pena (left oblique strain) played three innings in an extended spring game on Tuesday. He went 0-for-1 with a walk and a run scored. Pena played left field and didn't get any opportunities.