Payamps was diagnosed with a left calf contusion after leaving Thursday's game against the Yankees, Matt Kawahara of the San Francisco Chronicle reports.
Payamps exited Thursday's contest after being struck by a comebacker and being helped off the field, and it's unclear if he'll be available for the rest of the series versus New York this weekend. It was the 27-year-old's second appearance for Oakland after being claimed off waivers from the Kansas City last week.