It happened in 2010 when Romo broke his collarbone in the first half of a 41-35 loss to the New York Giants. The Cowboys fell to 1-5 at that point and were effectively done for the season.
The offense did not suffer in Romo's absence, especially after Jason Garrett was elevated to interim head coach after Jerry Jones fired Wade Phillips following a 1-7 start to the season.
Kitna, who was 38, finished the season with 2,365 yards on 209-of-318 passing with 16 touchdowns and 12 interceptions. In his seven games with Garrett as head coach the Cowboys went 4-3. In the six games he started and finished, the Cowboys averaged 32.2 points per game.
Two of the losses came by three points. One came on a final-second field goal after the Cowboys missed a point after attempt. Kitna had two three-touchdown games and two two-touchdown games.
The Cowboys ran the ball more and better down the stretch that season. They had three games with 400 yards of offense and had at least 100 yards rushing as a team in every game.
The system prevailed then with Kitna. Garrett needs his system to prevail Sunday against the Eagles with Kyle Orton as the starter.
"Kit played the last half of that season and played very well," Garrett said. "He and Kyle were probably at similar points in their career with similar number of starts, and they understand what we are trying to do offensively and they do a good job of playing within the system, getting guys involved and just playing quarterback the right way. So, that's what we have to do if Tony is not available to us, and we are excited to have that opportunity. If Tony can't play, just stick Kyle in there and go forward."