Mejia's next scheduled start would be this week against the Yankees at Citi Field.
According to multiple reports, Terry Collins talked with Mejia on field before Saturday's game and told the young pitcher that the team had yet to make a decision about next start, which is scheduled for Wednesday against the Yankees.
Mejia, 24, is 3-0 with a 5.06 ERA. He's averaging over 100 pitches and roughly five innings each start.
"You get a little concerned with the extra pitches he uses," Collins explained to reporters on Saturday.
Mejia insists that he's better suited for the starting rotation because of his history of arm injuries.