"It's better than it was before the injection, but it's still not completely resolved," manager Buck Showalter said of the injury, which is being labeled as tightness in the area where the forearm and elbow connect.
"Because of all the things that's going on, its actually good to get that peace of mind that what we are dealing with is actually the case. I think he's eliminated all doubt about the structure being good. It's good there."
The 30-year-old Hammel is 7-8 with a 5.20 ERA in 21 starts and has been dealing with the injury to a certain degree since Spring Training, with the team opting to place him on the DL when they acquired starter Bud Norris at the Trade Deadline.
"The doctors weren't able to identify a significant issue, so I'm hopeful he's going to come back and pitch for us," executive vice president of baseball operations Dan Duquette said. "We'll see how he goes. But, I know he wants to come back and pitch."
Brittany Ghiroli is a reporter for MLB.com. Read her blog, Britt's Bird Watch, and follow her on Twitter @britt_ghiroli. This story was not subject to the approval of Major League Baseball or its clubs.