UPDATE: Should have known the mystery team would end up being Toronto. The Blue Jays have announced that they are the club who claimed Guillermo Moscoso on waivers.
With the claim, Toronto's 40-man roster is now full.
After being claimed, Moscoso now has until March 20 to decide to accept the claim or become a free agent.
The Royals claimed Moscoso off waivers from the Colorado Rockies in November. The right-hander spent the 2012 season with the Rockies, appearing in 23 games -- including three starts -- while posting an ERA of 6.12 over 50 innings. He was in Triple-A for a majority of the season, where he maintained a 6.13 ERA over 18 starts.
Before being released by the Royals this spring, Moscoso appeared in three exhibition contests. 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 joining the Rockies last season.
Moscoso has spent parts of four seasons in the majors. His most significant stretch came in 2011, when he posted an ERA of 3.38 over 21 starts for the A's. During his time in the bigs, the 29-year-old owns a career ERA of 4.16.