He had yet to walk anyone and had given up just two hits and an RBI groundout by Ryan Howard. The Nats were on top 5-1 and all was well.
After whiffing Raul Ibanez, Domonic Brown came to the plate and ran a 1-1 count. On the next pitch, which ended up a ball, Strasburg suddenly grimaced in pain and shook his elbow.
Strasburg tried to talk his way into staying in the game, but after making the very visible grimace, there was zero chance of manager Jim Riggleman and the Nats allowing that.
It's not known how severe the injury is as the pain seemed to be brief. It may have just been a simple cramp, but are the Nats really going to take the risk? Even if Strasburg continues to report no problems, Washington would be best served to have the phenom right-hander undergo an MRI just in case.
Craig Stammen relieved Strasburg and got out of the inning unscathed to send the game into the sixth.
-- Evan BrunellFor more baseball news, rumors and analysis, follow @cbssportsmlb on Twitter.