The Rangers selected Viloria's contract from Triple-A Round Rock on Tuesday.
Viloria will join the 26-man active roster as a replacement for Sam Huff, who had been serving as the primary backup to top catcher Jonah Heim. Huff had also received some playing time at first base and designated hitter, but his opportunities to pick up starts were bound to take a hit with the Rangers bringing Mitch Garver (illness) back from the COVID-19-related injured list Tuesday. The Rangers still want Huff to play on a near-everyday basis, while Viloria's development isn't as much of a priority. With that in mind, the Rangers preferred to keep Viloria around in the majors, where he'll likely to play just once or twice a week when Heim needs maintenance.