Martinez is a 23-year-old outfielder prospect who has constantly battled leg injuries. He hit .227 with 1 home run for the Mets in 11 games in 2011. For Triple-A Buffalo last season, he hit .260 with eight home runs and 30 RBI. If Martinez clears waivers, the Mets could option him back to Triple-A Buffalo. Martinez has never played more than 29 games for the Mets in a season.
Herrera, a 27-year-old left-handed pitcher, was acquired from the Brewers last season in a trade. He pitched 8 innings in 16 appearances for New York last season. He was 0-1 with 1.13 ERA and five strikeouts. For his career, Herrera is 5-8 with a 3.72 ERA in 101.2 innings with 71 strikeouts.