Bradley woke up after his start on April 26 and felt a little more sore than usual, D-backs general manager Kevin Towers said.
Bradley flew to Phoenix, where a CT scan and MRI were performed and he was examined by team physician Michael Lee. The tests showed no damage to the ulnar collateral ligament.
"It came back as edema, there's a little bit of blood in there, swelling, but the UCL was intact. There was no fraying, it looked very, very strong," Towers said. "Dr. Lee said this is probably very, very minor. It was very good news. Probably no throwing for two weeks and then start him back up again, and hopefully in a month he's back throwing in games."
Bradley was 1-4 with a 5.18 ERA in five starts for Reno. He opened the season with two impressive starts, but then had three subpar ones. This past spring he pitched well in his first two outings, which put him in the mix for a rotation spot, but he faltered in his final two starts and they elected to option him to Triple-A.
"Maybe the same thing that happened in Spring Training happened here in the season," Towers said. "Started watching what our ballclub was doing, kind of sniffing maybe an opportunity to get up there and maybe trying to do a little too much. I don't know this, I'm just speculating this."
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.