"I'm worried about it; that's why I told them I was hurting," Hamilton said. "I hate coming out of a game so I really tried to battle through it as long as I could. It got to the point where it was bad and I didn't want to hurt it any worse. I hope it gets better. It still hurts me. We'll see where it goes from here."
It is the same shoulder Hamilton injured Aug. 18 trying to make a diving catch vs. the Royals. The following day, he was placed on the 15-day disabled list with a sprained capsule inside his shoulder. He was activated last Tuesday.
On Monday during the third inning, Hamilton had to make some long throws on balls hit into the outfield.
"A couple of balls that were hit into the gap, I threw them in and one on a relay," Hamilton said. "I ended up hurting myself. I felt it on the first throw and the second one came back-to-back and kind of hurt it again. It got to the point where I had to try and battle through it. I started swinging and it felt like it was getting worse."
Hamilton is batting .226 in 113 games this season with a Major League-leading 56 steals.
"We'll have to wait and see what the doctor says," Reds manager Bryan Price said. "Right now like we always say, it's a day-to-day deal. We'll have somebody take a look at him and come up with an idea on when he can come back, or if he can come back. I'm hoping he can come back and play for us. That's yet to be seen."
Mark Sheldon is a reporter for MLB.com. 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.