Romo suffered a broken collarbone in the second quarter of a 41-35 loss to the New York Giants Monday night. Kitna came in and completed 16-of-33 passes for 187 yards and two scores in his first regular-season action in more than two years.
"This isn't my first rodeo and we're going to be just fine," the 38-year-old signal-caller, now in his 14th NFL season, was quoted as saying on the team's Web site.
The Cowboys said Romo underwent a CT scan Tuesday that confirmed a fractured left clavicle. Team officials said the injury will not require surgery.
Kitna said he's ready to lead the 1-5 Cowboys for as long as necessary.
"It is not something that I am scared of or anything like that. I wish that this opportunity didn't come because I think it's bad for Tony, it's bad for this football team for that to happen," he said. "But it's here and I have confidence in myself and confidence in my teammates that we'll get some things ironed out. We'll start seeing things on the same wavelength and we will be fine moving forward."
Romo said he has confidence in Kitna.
"He's had some really, really great seasons," Romo said. "He's going to step in and he's going to do a great job for this football team. We're going to rally around Jon. He's going to put together some really great games. Jon is a good player and he'll show that."