He was called up to the Majors for the first time on September 19, 2010, after winning the Southern League championship with the Jacksonville Suns.

[1] In his MLB debut on September 23, 2010 against the Milwaukee Brewers, Rosario's first and third pitches thrown were hit as home runs.

Rosario started the 2012 season at the Marlins' Triple-A affiliate New Orleans Zephyrs and later pitched in four games for Miami, yielding six runs in three innings over four relief appearances.

After not receiving a September callup, Rosario was claimed by the Boston Red Sox on waivers on October 17, 2012.

On February 20, 2015, Rosario signed with the Delfines del Carmen of the Mexican Baseball League.