Romo suffered a fractured rib and a small puncture of his lung in Sunday's 27-24 come-from-behind overtime victory over the San Francisco 49ers.
Romo, while doing an interview with Showtime's "Inside the NFL" on Wednesday, said he is in so much pain that he's sleeping in a chair and it hurts when he laughs. Romo also had trouble getting out of his chair following the interview.
"We're going to take it day by day," said Romo, who put his hand to his chest while laughing at a joke by former New York Giants quarterback Phil Simms. "I know that doctors are looking at it each day and we're trying to figure out the stuff with the lung that hopefully we're done here in the next day or two. If it's just about dealing with pain, that's part of playing football and I know I'll be able to do that.
"I would assume as long as (that) stuff goes on the right track, I have a pretty good chance to make a decision to play here shortly."
Romo said the toughest thing about the injury is breathing without feeling pain and the unknown factor about the rib area that is damaged.
"This is my first time going through it this way," said Romo, who suffered a muscle injury to his ribs in the final game of the 2008 season. "I don't know exactly what it's going to entail. Like I said a little bit (ago) I'm going to take it day by day and see what (I) can handle and what (I) can't. Usually if it's a pain-related thing, it sucks. But you can usually play; either you can play and move around, or you can't.
"There's not really ... if it's an in-between thing, you usually end up playing. It's football season and usually football players play football during football season."
According to ESPN's Ed Werder, a source said Romo was measured this week for a protective vest to protect the rib area. The vest is manufactured by the same equipment company that created a similar device for Philadelphia Eagles quarterback Michael Vick last season when he suffered damaged rib cartilage.
Cowboys coach Jason Garrett said he's hopeful Romo can play on Monday; if not, expect backup Jon Kitna to be in the lineup.
"I think he's doing fine," Garrett said of Romo. "He got knocked around a little bit on Sunday but he's getting his rehab and hopefully he'll be ready to play for this ballgame. We'll take it day to day for the next few days."
Calvin Watkins covers the Cowboys for ESPNDallas.com.