As fun as it is to discover them, the Justin Herberts of this world are few and far between.

Which is to say, young quarterbacks that set the NFL on fire in their rookie season are a rarity. More often than not, rookie QB's coming out of college need time to adjust to the speed and complexity of the NFL.

Take the Bears; Justin Fields, for example.

While he showed flashes of his potential in the pre-season - his mobility, strong arm and ability to extend plays with his legs - he also showed that he was prone to making some ill-advised throws.

That's entirely understandable, as coverages are more varied and things happen quicker in the NFL. 

Not to mention, defenders are smarter and faster. Which means that even though you might have a cannon for an arm, it's unlikely you'll be able to fit the ball into a small window like you did in college.

Consequently, Fields is learning that, as he's also learning that he has to get the ball out of his hand quicker. Again, unlike college, you just don't have the time to scan the field and find an open receiver. 

You must go through your progressions quickly, identify your best option and get rid of the ball. If you don't, chances are you'll be steamrolled or separated from the ball by an onrushing lineman or linebacker who's intent on pounding you into next week.

It must be mentioned that Fields isn't the only rookie signal caller who's experiencing growing pains.

Zach Wilson is struggling in New York, while the first overall pick in the 2021 NFL Draft, Trevor Lawrence has also had his good and bad moments.

Meanwhile, in San Francisco, the 49ers are easing Trey Lance in, utilizing packages that are tailored to his strengths - which, at this time, is using his legs. 

Can he gain first down yardage on fourth and one? Certainly. Can he be a threat to take it in on the ground when the Niners are inside the 10 yard line? Absolutely.

But can he diagnose and exploit certain defensive coverages at this point? Not likely - he just doesn't have the experience at this point in time.

Heck, even in New England - where the offense has been simplified to make things easier on Mac Jones - the former Alabama standout has still experienced his share of ups and downs. That's as it should be. It's just harder to play quarterback at the NFL level.

Will Fields, Wilson, Lance, Lawrence and Jones be bonafide starters, and even stars, at some point?

The answer is likely yes.

But they all will need time to hone the skills they need to succeed in the NFL - learning how to navigate the pocket, recognizing defenses, learning when to eat or get rid of the ball, and knowing when they can (and when they can't) fit a ball into a small window.

That's why Andy Dalton will start again in Chicago when he's healthy, and why Lance will continue to serve as Jimmy Garropolo's apprentice, barring injury to Jimmy G.

As per usual, Wilson, Lawrence and Jones will continue to be inconsistent as they gain experience. 

It's just part of becoming a legit starter; just ask John Elway and Peyton Manning, both of whom struggled before attaining stardom.

The bottom line here? Don't depend on rookie quarterbacks to pile up fantasy points, as their inconsistency will make for too much variation from week to week. 

Stick with proven starters for the time being, while the Young Guns earn their spurs.