"I didn't overdo it," Harrison said. "But I did let it go a little bit and gave it some oomph to test the back out."
Harrison isn't sure what is next on his rehab plan but said his back felt "great" and he hopes to continue to ramp up.
Other injury notes:
* SS Jurickson Profar (shoulder tendinitis) said he felt fine after his throwing session (he's playing catch and was throwing from 70 feet) Wednesday and will continue to throw.
* RHP Tanner Scheppers (back) is scheduled to throw a bullpen session.
* Media relations guru Rich Rice sprained his ankle in a pickup basketball game. He's limping, but still working. Listed as day-to-day.