Cesar has quite the interesting transaction history, most of it occurring with the teams of the AL East. He was originally signed as an amateur free agent by the Red Sox back in 2005; the Rays then selected him in the 2010 Rule V draft. Over the course of 2 weeks during spring training 2011, he was picked up on waivers by the Blue Jays, then the Rays again, and eventually returned to the Red Sox. After the 2011 season, he was again taken in the Rule V draft, this time by the Royals, and then was purchased by the Yankees. Got all that?
He eventually made his MLB debut with the Yankees in September 2013, and would pitch a total of twelve games with the Evil Empire over the '13-14 seasons, ending up with a 7.71 ERA over 4.2 IP, so he's definitely a LOOGY (lefty one one guy).
The Orioles signed him to a minor league contract this past January, and he actually never even pitched for the big league club during spring training, so it's a pretty impressive feat for him to be off the radar in March and now pitching for the team in June. But that is what having a 0.00 ERA and 25 K's split between 21 games at AA Bowie(2) and then AAA Norfolk(19) will do for a guy. And he's been good with the O's so far too, with two hitless/scoreless appearances totaling an inning of work.
Keep up the good work Cesar!