He'd experienced no lingering effects of being beaned in Tuesday night's win over the Twins.
"No headaches at all," Cain said. "I'm ready to go."
And he talked about how good his legs were feeling. He'd missed 78 games with a groin strain and a torn hip flexor, both in his left leg. It had been a long haul to get back.
"Injuries or stuff just seem to find me this year," he remarked.
Just hours later, Cain had to leave in the 10th inning of a 4-3 walk-off loss to the Twins when he strained his right hamstring while trying to make a catch of Alexi Casilla's double. He walked off the field with just a slight limp and the injury was not believed to be serious, but he'll be re-evaluated on Friday in Kansas City.
Center fielder Jarrod Dyson is already on the sidelines with a strained lat muscle that has kept him off the field except to pinch-run.