For the 2014 season, Otero served as a mainstay in the A's bullpen, pitching a career high 72 games. He was 8-2 with a 2.28 ERA in innings. On September 30, 2014, Otero was the losing pitcher in the 2014 American League Wild Card Game, giving up two earned runs in the bottom of the 12th inning. He struggled the following season, appearing in 41 games but having an ERA of 6.75 in innings.