The Jacksonville Jaguars offense is riding high this preseason. Second-year quarterback Blake Bortles has looked like a legitimate franchise quarterback, the offensive line could be the most improved offensive line in the league from 2014 to 2015, and the wide receivers are no longer a group of rookies learning as they go. Heck, I'm not even as worried about an underperforming running game because the passing game has looked that good.

But you wouldn't know it talking with Rivers McCown from Football Outsiders.

We asked him about the offense -- Bortles and the offense in general -- and he's not ready to concede that this unit will improve year over year.

What we saw last year was a handsome man who played quarterback like he’d been put there by the witness protection agency. I do think Jedd Fisch asked a lot from him in terms of not giving him many checkdown targets last season, so a change there could help.

Let's stop right there. Bortles wasn't given many checkdown targets? Bortles threw 21.8% of his passes behind the line of scrimmage last year. And only 26.9% of his passes were 11 yards or longer in the air past the line of scrimmage. Compare that with Ben Roethlisberger (32.0%), Derek Carr (29.5%), and Brian Hoyer (39.5%) who threw far more passes 11 yards or longer in the air.

The (first) preseason game was a nice start, but we saw last year that a hot preseason doesn’t necessarily translate into success.

No, we didn't. If you watched the games last year, they were filled with broken plays and sandlot throws. Do you really think Bortles could have made a throw like this in his rookie season?

Or do you think he could have stepped up, looked for options downfield, and then thrown successfully to his check down option like he did here last week?

The answer is unequivocally no.

I wish the Jaguars would’ve brought in an offensive coordinator more focused on quarterback development, but like I said, you could tell Five Months From Now Me that Bortles repeated last season or you could tell me Bortles was a borderline star. I wouldn’t be shocked by either extreme.

Olson's offense is absolutely perfect for a quarterback's development. Not only do we have the personnel in Julius Thomas and Marcedes Lewis to play up Olson's tendencies to take what the defense gives us underneath, but he brings a read-and-react system which favors a young quarterback. Bortles literally just bounces through reads until he gets to his open option (usually a tight end underneath or a receiver sitting in zone) instead of having to pick apart a defense or time his receiver's route.

Not only that, but Olson's scheme only elevates Bortles' mobility. By being able to get outside the pocket, Olson can exploit matchups through extended routes by quicker running backs (Denard Robinson) and athletic tight ends (Julius Thomas and Clay Harbor).

If forced to bet, I’d say he’s got too much ground to make up to be a good NFL quarterback.

Well, this I can't prove outright wrong. I can't prove Bortles won't be a good NFL quarterback. I can't say he'll make up any ground he lost last year.

But from the change I've seen through the preseason this year, I can say it's a bad bet.