And, more importantly for the Eagles, if anyone other than Vick plays, then the team doesn't win.
For the second time in as many weeks, Kafka was forced into spot duty after Vick suffered an injury, this time a broken right hand against the New York Giants. Vick came down with the break on the penultimate play of a long, methodical drive that ultimately concluded with a 21-yard field goal to put the Eagles up 16-14.
Vick came back for Philly's first drive of the fourth quarter but didn't return after that, leaving Kafka once again to lead his team back from a late deficit, this time down by six points.
After spending most of the game to that point as a run-centric attack, the Eagles' offense immediately shifted exclusively to the air, to disastrous effect. Both of Kafka's drives ended in interceptions on deep throws to DeSean Jackson, thereby helping the Giants to close the book on the Eagles in a 29-16 defeat.
It's tough to blame Kafka too much for his failings to this point. Kafka had never thrown a regular-season pass before this, his second NFL season. What's more, Kafka's been thrown into difficult situations in each of his appearances thus far, his first minutes of playing time coming late in the third quarter against the Atlanta Falcons with the Eagles already down 10 points.
Kafka came into the season as the second-string quarterback for the Philadelphia Eagles after free-agent signee Vince Young succumbed to a hamstring strain in training camp. Young should be healthy enough to play within the next week or so, though, Kafka remains the more familiar of the two with regard to Marty Mornhinweg's offense.
Kafka won't receive much sympathy for his shortcomings to this point, nor should he expect any. The NFL doesn't award points for excuses and hardships, no matter how dire the circumstances may be.
That being said, no one should expect Kafka to flourish this season, especially if he's going to be thrown to the wolves as Vick's primary substitute. Kafka might've been fine last year, when the Eagles still ran a system designed for a pocket passer like Kevin Kolb but saw Vick put up a monster season anyway.
Now, though, the odds are firmly stacked against Kafka, even if he ends up starting from the first snap. With Kolb gone, the Eagles have since tailored their attack to Vick's particular talents, and for good reason. The team invested big money in Vick and, frankly, the offensive line is so bad that the team needs a quarterback with Vick's shifty feet and ability to throw on the go to be successful.
Chances are Kafka won't be able to do even half of what Vick is capable of on a football field. To ask that much of him would be unfair, seeing as how no single player in the league comes anywhere close to effectively mimicking Vick's incredible skills.
Not even Vince Young, as mobile as he may be.
But that won't keep Kafka from shouldering the blame for the Eagles' failings, as hard as his teammates may try to shield him from the merciless boos of fans in Philadelphia. The Eagles' next three games read like a list of the NFL's most dangerous resurgent squads—home against the 49ers, at the Bills and at the Redskins.
That's shaping up to be quite a gauntlet for young Kafka, one that, short of a wholesale Metamorphosis of the quarterback into a Michael Vick clone, won't play out well for him or the Eagles.