Andrea Bargnani ready for No. 1 role?

How will Chris Bosh's departure affect Andrea Bargnani's production this season?

The laws of fantasy dynamics dictate that Chris Bosh's defection from the Toronto Raptors to the Miami Heat should result in a 20-30 percent boost in Andrea Bargnani's points and rebounds per game.

The signs are all there: Skilled young big man with the pedigree of being the No. 1 overall draft pick and an evolving all-around game spends early part of career riding shotgun to an established Alpha Dog. Alpha Dog moves on, skilled young big man ascends to the Alpha Dog spot, and fantasy goodness ensues. It's an easy path of logic to follow, and Bargnani has been edging up draft boards accordingly.

In a preseason where healthy centers have been in short supply, many fantasy owners, including me, have been anxious to enlist Bargnani's services. I've always been a big fan of Bargnani. He's the kind of player who is better in fantasy than in NBA reality (sort of the anti-Kendrick Perkins), with a unique mix of 3-pointers, blocks and solid percentages with center eligibility. He's long been one of the NBA's worst rebounding big men, but Bargnani has steadily improved in that area every season (ticking up to 6.2 per game in 2009-10).

Instead of having the kind of preseason his prospective owners have expected -- 20 points and 7 rebounds a game sounds about right to me -- Bargnani has struggled mightily on the offensive end. Until Sunday's game against Phoenix (in which he broke out a bit with 15 points in 25 minutes), Bargnani has looked scary (and not the good scary) from the field, shooting a combined 16 for 64 for a .250 percentage.

Because his single greatest fantasy strength is his perimeter shooting, you'd like to write off Bargnani's anemic performance as some kind of preseason aberration. But for the owners -- and by "owners," I mean me -- who took "The Magician" in the late fourth round, I'm sure they'd like some assurances that Bargnani's going to right the ship before opening night.

His negatives are traditionally in the areas fantasy owners don't care about. Most leagues don't count "defensive focus" in their scoring system. But that lack of defensive commitment hasn't just plagued Bargnani. The Raptors were one of the NBA's worst defensive teams last season. So coach Jay Triano decided to ratchet up the team's defensive focus this preseason. Some team observers have noted that the extra work on the defensive end has translated into Bargnani's lack of offensive punch.

Another reason the Raptors have had trouble overall finding a groove on offense has been all of the turnover in their rotation. Post Bosh, the Raptors are essentially going into a rebuilding year (starting that sentence "Post Hedo Turkoglu" didn't quite have the same heft). With so many players in new roles, an adjustment period is to be expected. Any time you start penciling in Reggie Evans as your starting power forward, there will be some negative repercussions. (Let's all hope for all of our sakes that Amir Johnson will reclaim his rightful spot, and soon.)

The bit about Bargnani not adjusting to being "The Man" on offense isn't quite fair. When Bosh went down late last season with an ankle injury, Bargnani stepped up and did fine, averaging nearly 20 points per game down the stretch. I believe this group of games provides a better barometer for pegging Bargnani's value by the end of the upcoming season, as opposed to a few middling preseason games.

Bargnani could shoot 16 for 600 in the preseason and he's still going to be Toronto's No. 1 offensive option come opening night. He's going to get his numbers, even if he isn't as efficient as he's been in recent seasons.

What he's going to need more than anything is some other reliable scoring threats to emerge in the Raptors rotation.

Thankfully, rising fantasy sleeper Linas Kleiza appears to stepping into Bargnani's old role as the team's No. 2 option. But it's going to take more than Kleiza's 3-point shooting to take the pressure off Bargnani. In the end, what will be required is someone on the Raptors to providing some interior punch. Until that happens, their lack of a face-up players (one of Bosh's many talents) is going to hurt Bargnani more than his coach politely requesting he play defense. And that face-up guy is most definitely not going to be Evans.

Maybe Ed Davis will eventually become that guy. Until then, it's safe to expect Bargnani will get his 20 ppg, but it might take 24 shots a night to get there.

John Cregan is a fantasy basketball analyst for ESPN.com.