From the official Twitter account of the Oakland Athletics …
#Athletics recall Ryan Cook from Nashville; option Kendall Graveman to Nashville
— Oakland Athletics (@Athletics) April 26, 2015
Graveman allowed six earned runs in 4 2/3 innings Saturday in a loss to the Astros, falling to 1-2 on the season with an 8.27 ERA and 2.02 WHIP in 16 1/3 total frames (four starts). Susan Slusser of the San Francisco Chronicle says right-hander Jesse Chavez, who opened the 2015 season in the Oakland bullpen despite posting a 3.45 ERA across 146 innings last year, will take over the vacant rotation spot.