"First bullpen in the books," Strasburg wrote on his Twitter account after throwing off a mound at the team's extended Spring Training facilities in Viera, Fla.
"Felt great!" Strasburg wrote. "Hopefully time will speed up now!"
Manager Jim Riggleman downplayed the significance of Strasburg's outing.
"That basically means he's on the slope instead of flat ground," Riggleman said. "It's probably 50 percent effort-wise. It's the next step in the rehab -- to get him throwing downhill, instead of on flat ground."
Strasburg, the No. 1 pick in the 2009 First-Year Player Draft, went 5-3 with a 2.91 ERA in 12 starts last year before being removed from a game at Philadelphia on Aug. 21, due to the elbow injury. The surgery to repair Strasburg's ulnar collateral ligament was performed by Dr. Lewis Yocum in Los Angeles.
There is an outside chance Strasburg could return to the Nationals this year. But it is more likely he would rejoin the club in 2012, if his rehab is successful.