Whalen is on crutches after tweaking his calf Thursday, Bob Dutton of The Tacoma News Tribune reports.
It's another bad break for Whalen in what has already been a rough spring. The right-hander has been struggling to prove his value as a starter while posting a 12.00 ERA in just three innings of Cactus League action. Whalen will likely begin the 2017 season at Triple-A Tacoma after being acquired by Seattle in an offseason trade, but this injury could put him on the DL to begin the campaign.