Although was clearly wincing when he threw his final pitch, as you can see in this photo, manager Jim Riggleman says Stephen Strasburg wanted to stay in the game, according to Gene Wang:
"After the initial feeling that he felt, by the time we got out there, he said, you know, 'I feel good. I don't even feel anything. Let me keep pitching,'" Riggleman said. "We just didn't choose to do that."
The MRI on Sunday will tell us much, much more, but Strasburg's attempt to stay in the game provides a glimmer of optimism as we anticipate the results.