Cronin is managing left hip discomfort and won't be included on Miami's Opening Day roster, Christina De Nicola of MLB.com reports.
The right-hander surrendered nine runs in 5.2 innings during spring training before Miami backed off his throwing program due to the hip issue. Cronin made 56 appearances for the Marlins last year and had a 4.35 ERA, 1.42 WHIP and 72:25 K:BB over 70.1 innings. It's unclear how long he's expected to be sidelined by the hip issue.