Castillo, who turns 34 in a week, has made his way around the Minors, MLB, and independent leagues since 2004. At 18-years-old, he was signed by the Diamondbacks as an amateur free agent out of the Dominican Republic. He made his MLB debut for the Reds in 2008. After appearing in 18 games that season and four in 2009, where he hit .314/.333/.343, Castillo has not touched a Major League field since.
He spent several years at the Triple-A level and then opted to play a couple seasons in the Mexican League at the start of 2013. In 2015, he made his way back to the Minors, still playing Triple-A ball. Castillo has been through seven Minor League systems, including a season with the Yanks organization in 2017. Between 59 games with the RailRiders and Trenton Thunder, he owned a slash line of .193/.243/.286 with three home runs and 13 runs batted in.
After last season, Castillo took his talents to the Atlantic League, an independent professional baseball league. He played 19 games with Long Island before being brought back to the Yankees. In those contests (.308/.400/.492) he hit four doubles, a triple, two home runs and drove in 12.
Collectively, Castillo owns a .265/.307/.367 slash line. He has experienced the bulk of his career in the minors, mainly at the Triple-A level. It seems that he will act as injury insurance and take on a role player lead. In addition to catching, Castillo played third base, second base, shortstop, first base and right field in his 15 year career.