Cotton left the Athletics' June 23 contest with the White Sox because of a blister on his right thumb, and he had his subsequent start pushed back because of it. The rookie righty has a 5.17 ERA in 14 starts this season.
Worth noting
It was also announced Thursday that A's head athletic trainer Nick Paparesta with head the American League training staff for the 2017 MLB All-Star Game presented by Mastercard on Tuesday.