Harrison (elbow) underwent an MRI over the All-Star break and is aiming to throw a bullpen session Saturday, Adam McCalvy of MLB.com reports.
Harrison landed on the 15-day injured list last weekend with tightness on the outside of his left elbow. The MRI results have not yet been read by the doctor, but that will occur later Friday, and if Harrison is cleared of structural damage, he will resume mound work this weekend.