Mazzoni, 24, was 4-3 with a 4.45 ERA in 12 starts for Double-A Binghamton last year, during which he struck out 73 batters and walked 19 in 64 2/3 innings pitched.
He was drafted in the second round in 2011, and was ranked the team's 15th-best prospect by MLB.com entering the 2013 season.
Mazzoni's FIP is a full run lower than his ERA, so he's probably a slightly better pitcher than his 4.45 ERA might suggest. Frankly, he sounds like he's a younger Bobby Parnell, according to the way Mets people talk about the velocity and command of his fastball and secondary pitchers. Similar to Parnell, who started out as a starting pitcher, Mazzoni's repertoire may be best suited for the bullpen. Also like Parnell, when making a similar shift to the bullpen, his career could go one of two very stark directions. If Rubin is correct, that shift may come sooner than later.
By the way, the bullpen competition is going to be very fun to watch. In addition to Parnell, it looks like Vic Black, Jeurys Familia and Gonzalez Germen may be locks for the staff. However, Josh Edgin, Scott Rice, Mazzoni, Jack Leathersich and Jeff Walters, plus any acquisitions that have yet to me made, will all be competing for spots, as well.