The Padres selected Salas' contract from Triple-A El Paso on Tuesday.
The Friars' top prospect, Salas is joining the big-league club for his first look in the majors. The 20-year-old was promoted to the Triple-A level in late July and carried a hot bat in his 24 games at the highest level of the minors with a .326/.410/.539 slash line in 105 plate appearances. Salas should see plenty of reps behind the plate for the Padres down the stretch, with Freddy Fermin -- who is starting Tuesday in Cincinnati -- and Luis Campusano likely to mix in occasionally.