The Twins ultimately decided to remove Mastroianni from the roster to open a 40-man roster spot for the newly signed Kurt Suzuki after Chris Colabello refused to move to Korea.
Needing a 40-man roster spot after signing Kurt Suzuki, the Twins reportedly were interested in selling Chris Colabello's rights to the LG Twins in South Korea. However, after Colabello nixed that transaction, the Twins were forced to find another way to clear space for Suzuki. They announced just minutes ago that their decision was to outrightDarin Mastroianni to Triple-A Rochester.
Mastroianni originally made his debut with the Toronto Blue Jays back in 2011 because then-second baseman Kelly Johnson forgot his passport in Arizona, who then had to fly back to retrieve it. Mastroianni played in only one game that season, and then was designated for assignment prior to spring training in 2012.
The Twins then claimed him off waivers and sent him to Double-A New Britain, where he hit a meager .143/.231/.171 in 40 plate appearances. Nevertheless, he was called up to Triple-A Rochester where he triple-slashed a much better .346/.393/.423 with 10 stolen bases in only 85 plate appearances, and he was eventually called up to the majors in May 2012. He hit .252/.328/.350 in 186 plate appearances while mostly playing the outfield corners, but where he showed his best talent was on the basepaths. In less than half a season, Mastroianni stole 21 bases in 24 attempts (88%), which tied Alexi Casilla for 2nd most on the team behind Ben Revere's 40, even though Casilla had nearly twice as many plate appearances.
Mastroianni started 2013 as the 4th outfielder for the Twins, but suffered an ankle injury just before the season started when he fouled a ball into his leg. What was initially a mild ankle problem became a stress reaction and later he underwent surgery to fix it, causing him to miss most of the season. He did receive a call-up late in the season, but only mustered a .185/.229/.215 line in 73 plate appearances (30 games).
He was in line to compete for a backup outfielder job in 2014, but that seems unlikely now with his removal from the 40-man roster. Since he was outrighted, the other 29 teams had a chance at claiming him but all passed, meaning he will definitely remain in the Twins organization for the near future.
Because of his ability to play all three outfield positions and his baserunning ability, I feel that with a few breaks (no injury-related pun intended) he could still find his way back in Minnesota at some point next year, with Aaron Hicks still being a question mark and Alex Presley never being a full time center fielder, though admittedly Mastroianni has only 8 major league starts in center field himself.