Hammel, who left his Sept. 11 start with discomfort, said there is still some irritation in his knee but it's gradually getting better each time out.
"Maybe I came back a little bit too quick," said Hammel, who missed about two months after undergoing arthroscopic knee surgery and made his return from the disabled list Sept 6. "Usually when your body feels good you want to give it an extra week, so it was good that there was no extra damage [shown on the MRI] Just re-aggravated.
"I'm not going to get on a mound until it feels good. Honestly, I know that I can help the team, but we're looking further down the road here. If it's something I can re-aggravate further or reinjure or either my arm, who knows what's going to happen? We are just going to be a little cautious with it and hopefully I can come back soon."
When healthy, Hammel has been the Orioles' best starter. He owns a 3.43 ERA in 20 starts despite dealing with knee discomfort for two months before undergoing surgery.
"It's a lot further along than it was," manager Buck Showalter said. "[Pitching coach Rick Adair] and [Hammel] have talked about trying to look at a delivery that might take a load off that knee, which is something he was doing earlier in the year, but we'll see. Obviously [I'm] not going to pitch him if he still feels discomfort."