Cashner, who has been on the disabled list since April 6 with a strained right rotator cuff, was to make three to four appearances with the Smokies, then go to Triple-A Iowa. He will likely start the first couple of games, but only pitch one inning each time as he builds up arm strength.
"I've been ready to go for a while now," Cashner said. "I'm looking forward to the opportunity to playing again and getting healthy."
Cashner, who turns 25 on Sept. 11, won a spot in the rotation out of Spring Training but was expected to pitch only in relief when he rejoins the Cubs.