Mets manager Willie Randolph informed Martinez of the roster move after the team's win over the Indians. Martinez, along with pitchers Nate Field, Tony Armas and Joselo Diaz, will report to Minor League camp on Thursday.
Martinez, 19, hit .340 over 18 Grapefruit League games, logging significant playing time with fellow outfielders Carlos Beltran, Ryan Church, Moises Alou and Endy Chavez all nursing injuries. Widely considered the top prospect in the Mets organization -- and among the best in all of baseball -- Martinez said earlier this spring that he hoped to be with the club by September.
"He's confident, obviously, and that would be awesome," Randolph said. "He's very talented, so I can see him setting that goal, and hopefully he's going to reach that."
Field, Armas and Diaz all boasted Major League experience coming into camp, though as non-roster invitees they remained long shots to make the club.
Anthony DiComo is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.