Mateo was optioned to Triple-A Nashville on Tuesday, Jane Lee of MLB.com reports.
Mateo had a terrific game Tuesday against the Royals. The 22-year-old went 2-for-4, with both hits being home runs. However, with Jed Lowrie and Marcus Semien at second base and shortstop, respectively, it seemed likely that Mateo would return to the minors before the 2018 season got underway. After logging a .292/.333/.518 line over 30 games at Double-A Midland following his trade from the Yankees last season, Mateo will have his first chance to play at the Triple-A level.