"Considering he's coming off the seven-day concussion DL recently, it's not a formality," Reds manager Bryan Price said before the approval. "It's something he has to go through, through MLB, to verify there hasn't been a re-injury, concussion issue. There are protocols he has to go through."
Hamilton suffered a facial contusion when he was struck by an Anthony Rizzo fly ball on the left cheek in the first inning of a 9-2 loss to the Cubs on Wednesday. After the ball grazed left fielder Adam Duvall's glove as he and Hamilton converged, it hit the center fielder's face and ricocheted to the wall for a three-run inside-the-park home run.
After he banged his head sliding into third base while attempting to steal on June 8 vs. the Cardinals, Hamilton was on the 7-day concussion disabled list from June 10-16.
• Reds pitcher Alfredo Simon, on the disabled list since June 22 because of a strained right trapezius muscle near his shoulder, has yet to resume throwing.
"He's got a massive spasm in his right trapezius," Price said. "It's really limiting any type of throwing mobility whatsoever. He's had relief, but not total relief to the point where he's been greenlighted to go out and resume activity."
• Reliever Caleb Cotham, who went on the DL with right shoulder inflammation May 31, began a rehab assignment with Double-A Pensacola on Thursday. Cotham is expected to make at least five appearances with that club.
• Third baseman Nick Senzel, the No. 2 overall pick in the 2016 Draft, was promoted to Class A Dayton on Thursday. Senzel batted .152 with four RBIs in 10 games with Rookie-level Billings.
Mark Sheldon has covered the Reds for MLB.com since 2006, and previously covered the Twins from 2001-05. Read his blog, Mark My Word, follow him on Twitter @m_sheldon and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.