With the release of Moscoso, the Royals now have 39 players on their 40-man roster.
Moscoso spent the 2012 season with the Colorado Rockies. He made 23 appearances, including three starts, posting an ERA of 6.12 over 50 innings. The right-hander spent a majority of the season with the Rockies' Triple-A affiliate. He maintained an ERA of 6.13 over 18 starts.
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The Royals claimed Moscoso off waivers from the Rockies in November. He appeared in three games for the club this spring prior to his release. Over three appearances, including one start, he allowed five runs on seven hits with three walks and four strikeouts.
Moscoso came up through the Detroit Tigers minor league system before being traded three times since 2008. He was dealt to the Texas Rangers and then the Oakland Athletics before landing with the Rockies last season.
He's pitched in parts of four seasons in the majors, though he only made one appearance in 2010 while with Texas. He did start 21 games for the A's in 2011, posting an ERA of 3.38 with a strikeout-to-walk ratio of 1.95. During his time in the bigs the 29-year-old owns a career ERA of 4.16.