"We've still got about 48 hours to the game," coach Jason Garrett said Friday, "so we're going to give him every chance."
Romo has been receiving treatment on his back all week but has not done any football activities. The Cowboys have a walkthrough Saturday morning as their final preparations for the Cardinals' game.
If Romo plays, the equipment staff has sewn extra padding into his undershirt.
Owner and general manager Jerry Jones said on 105.3 The Fan in Dallas that Romo is "moving around, and he's doing a little stuff in the back there to get the stiffness out, kind of like a bicycle-type thing. He's moving around, been in the meetings today."
"I feel ready. I'm confident," Weeden told ESPN's Ed Werder. "The uncertainty is the only thing. What's the word? We going to do this? That will come, but I just have to prepare like I'm going to play and expect the unexpected."
"Even though [Weeden] doesn't have a lot of playing experience, he's very calm and poised in there," Cowboys tight end Jason Witten said. "I think it helps that he's worked with us once a week for the first seven or eight weeks. I think he's done a good job. Hopefully, Tony will be out there."
Left guard Ronald Leary is missing his third straight day of practice, as well, with a groin injury. Garrett said Leary took part in Friday's walkthrough. It is possible Leary could be active but not start. Mackenzy Bernadeau would start.
Linebacker Bruce Carter, who broke his left ring finger in Thursday's practice, is taking part in Friday's session, as is Rolando McClain, who missed Wednesday's practice. Defensive end Jeremy Mincey is sick and not practicing on Friday.
ESPN's Ed Werder contributed to this report.