Though Washington has assembled a cadre of young pitchers -- the emphasis of its franchise-building blueprint -- Zimmermann already has distinguished himself. He had a fastball in the mid-90s and true ace potential, something Washington's other pitchers lack. Zimmermann's injury heightens the conundrum facing an organization that now has six days to sign No. 1 pick Stephen Strasburg. With Zimmermann gone, the team needs Strasburg more than ever. Zimmermann's injury, however, provides an unsettling reminder about the tenuous nature of pitching arms, and investing therein.