He made the 2010 Opening Day roster, at 20 the youngest player in the majors. He twice ranked as the top prospect in the system.
This season Mejia finds himself further down on the organizational totem pole. Tommy John surgery will do that to a hard-throwing prospect. The 22-year-old had the procedure performed last May, and he's not scheduled to return to games until a month into the season.
"I have to work harder than I did in 2010," Mejia said the day he arrived at camp. "I know I can't make the big league team right now, because I had Tommy John—but I have to be ready for it."
Mejia made just five starts for Triple-A Buffalo last season before going under the knife. In the interim, a trio of power righties—Zack Wheeler, Matt Harvey and Jeurys Familia—passed him on the Mets depth chart.
The Mets will continue to groom Mejia as a starter this season. That's the routine with which he's most familiar, though questions remain about the 6-footer's viability as a starter. Big league pitching coach Dan Warthen has expressed his worry about the natural cutting motion of Mejia's fastball delivery, which "causes a lot of torque on your elbow and shoulder."
"I think Mejia works really hard to throw the baseball," Warthen said. "I worry about the volume of the pitches."
In the bullpen, Mejia could unleash his arsenal without worry. His fastball touches the high 90s, and his changeup often is a plus offering. When his curveball is working, the combination is outstanding. But injuries have limited Mejia's progress, and he never has pitched 95 innings during a season.
"Sometimes I feel tight," Mejia said of his reconstructed elbow. "Sometimes I feel good. That's the situation."
• Righthander Brant Rustich, a second-round pick from UCLA in 2007, returned to the mound in early February after missing last season with nerve damage in his right shoulder. The Mets once expected Rustich to advance quickly to the big leagues, but chronic arm trouble has limited him to 67 career appearances.
• Like Rustich, outfielder Sean Ratliff missed all of last season but had returned in time for spring training. The 2008 fourth-rounder endured several surgeries last spring after a foul ball struck him in the right eye, nearly detaching his retina.