Jason Grilli (oblique) will throw on back-to-back days sometime during the Pirates' six-game homestand that begins on Tuesday. It could be the last step before he's activated, so a return by the end of the week seems possible. It's not clear whether the appearances will come in more simulated games or if Grilli will go out on a short rehab assignment. He threw a simulated game Saturday with no issues. "Followed the glove very well," manager Clint Hurdle said. "I thought the breaking ball shaped up better than last time out, sharper. Threw some changeups. I thought it was a very good step forward for him."