"I don't think we can say anything 100 percent right now," Romo said Friday. "It's just a matter of the day and keep getting better. I'm obviously planning mentally going out there, so we'll see."
A CT scan on Thursday revealed the puncture of Romo's lung had healed, but he has not practiced the last two days and is not sure he would be able to practice on Saturday.
"There is nothing that has been cleared 100 percent either way," Romo said. "We've been cleared with the pneumothorax. That part of it was the first step. There are a couple of steps in the whole process and we'll take it as it comes. As I said, if it has to do with dealing with the pain, it's part of playing quarterback in the NFL."
Romo has done some light throwing over the last few days and was fitted for a protective vest on Wednesday. A source tells ESPN's Ed Werder that he was out Friday because the Cowboys didn't want to inject him with a painkiller. If he plays Monday, Romo will likely receive an injection, according to a source.
"I think I'll be protected," Romo said. "The equipment room guys have done a great job of going in there three or four times, going through different stuff. I think we have a pretty good plan. It's something that'll be very stable. They've done a good job, I think, so far. I'll have to test it out as we get closer, but [it's] not affecting my throwing motion and things of that nature."
Romo said the pain remains but has not completely subsided, but he said this was different than the rib cartilage injury he suffered in the 2008 season finale at Philadelphia when he collapsed in the shower after the game. His treatment this time has included a bone stimulator attached to his side.
"The doctors and training staff have talked extensively with me about the whole situation and what everything entails," Romo said. "That's something you take into account. If there was an opportunity or chance you could really do something that could be really damaging, obviously I think we wouldn't put someone in that position. If I go out there, you feel pretty confident you're in the clear in that regard. Now obviously, when you have an injury stuff can happen."
Todd Archer covers the Dallas Cowboys for ESPNDallas.com. Calvin Watkins of ESPNDallas.com contributed to this report.