The Athletics recalled Serven from Triple-A Las Vegas on Sunday.
The 31-year-old had two brief stays in the majors during the first half of July and may now get a longer opportunity due to Shea Langeliers (knee) landing on the injured list with a torn meniscus. Serven has gone 1-for-4 in two big-league games this season, though he's been productive in the hitter-friendly Pacific Coast League for Las Vegas with a .939 OPS in 61 contests. He'll serve as the backup catcher to fill-in starter Jonah Heim.