Rosario was optioned to minor-league camp Tuesday.
Rosario had a strong spring at the dish for the Mets, but the 21-year-old is still in need of further refinement in the minors, so he wasn't under consideration for an Opening Day roster spot. However, if David Wright's rehab from a shoulder injury ends up lingering through much of the season and Rosario rakes at the Triple-A level like he did with Double-A Binghamton in 2016, the young infielder could be in line for his first taste of the big leagues at some point in the summer.