But Cassel will start his seventh game Saturday night against the New York Jets, even though he's 1-5 as a starter with five touchdowns and six interceptions.
Jason Garrett's decision to keep Cassel at the helm tells us a lot about the Cowboys' coach, who will finish under .500 for the first time in his six seasons as head coach.
Garrett is not the Howdy Doody character he portrays to the public, nor is he Jerry Jones' ventriloquist dummy as so many of you think. He has an affinity for dropping F-bombs and is ultracompetitive.
Understand, Garrett has spent his entire tenure as coach creating and maintaining the Cowboys' current culture.
Why do you think he had navy T-shirts made with "Fight" written across the chest? And why do you think he's always talking about the relentless spirit of his last-place team?
Garrett has stood in front of his team every day for the last six years preaching the importance of fighting and competing on every play of every game. Benching Cassel and naming Kellen Moore the starter would essentially tell his players the season is over. And that would undercut the entirety of Garrett's message.
"The evaluation is who gives us the best chance to win Saturday night," Garrett said, "and we still feel like Matt Cassel is that guy.
"You're always looking to evaluate young players, but our sole objective right now is to win this game Saturday night."
Don't forget, Dallas still has the slimmest of playoff hopes. If the Cowboys can win three straight games, something they haven't done all season, and the New York Giants, Philadelphia Eagles and Washington Redskins each go 1-2, then the Cowboys will make the playoffs.
No one is flying to Las Vegas and betting their paycheck on that series of events, but until it's mathematically impossible for the Cowboys to make the postseason, there's no need for Garrett or his players to quit on the season. Once they do get eliminated, then Garrett will make a switch at quarterback.
When asked if Moore will get some practice reps with the first-team this week, Garrett said, "I don't really want to get into any of that stuff. Matt is our starting quarterback, so we'll prepare him to be our starter. Kellen will mostly do scout team stuff like he's been doing the last couple of weeks."
Sounds as if Moore will get a smidgen of work with the starters, right? That said, those of you clamoring for Moore were probably the same folks clamoring for Cassel after Brandon Weeden went 0-3 as a starter.
We see how well that has worked out.
Garrett and playcaller Scott Linehan have consistently said the quarterback's performance isn't the sole reason why the Cowboys have one of the NFL's worst offenses this season.
It's the offensive staff. It's the playcaller. It's the scheme. It's the players. It's everybody.
Moore, whenever he gets a chance, isn't going to fix the litany of problems on this offense. There's probably a reason he has yet to throw a regular-season pass in four NFL seasons.
In four preseasons with the Detroit Lions, the Boise State product -- who's generously listed at 6 feet, 200 pounds -- completed 135 of 224 passes for 1,350 yards with nine touchdowns and four interceptions. None of that helped him get on the field in Detroit or Dallas. And, for now, he's OK with that.
Moore says he understands his role on the Cowboys and he'll be ready to play, if and when he gets a chance.
He does scoff at the notion he's not big enough or his arm isn't strong enough to play in the NFL. He has the confidence of a 50-3 record as a starter in college and a fourth-place finish in the 2010 Heisman Trophy balloting as a junior.
"He's a cool customer," Linehan said with a smile. "His anticipation and timing and feel for game are good.
"He sees things as they develop. It's not like he has to have a guy open to pull the trigger. He has an uncanny knack and feel for the game and he brings a calmness to the position."
As soon as the Cowboys are officially eliminated from the playoffs, we should get a chance to see Moore for ourselves. But until then, he'll be watching Cassel like the rest of us.