In the court of public opinion, Heck has won the day. Kirk knows this, and I believe that's why he'll trot him out first. Every opportunity Brown has had in front of fans has been negative, while Heck has only been positive. If Heck somehow looks bad against NIU in the first few drives, it'll be easier to sub him out for Brown.
Ultimately, reading between the lines from Kirk's interviews, I firmly believe this is a Lester decision and Kirk will support it. Kirk knows he's struck out a few too many times when selecting a QB, so I think this time he'll defer to Lester who is much more knowledgeable, especially considering how close this race supposedly is. And if it is Lester's choice, he'll go with Heck because Lester prefers a gunslinger willing to extend the play and take risks rather than a safe check down charley.
Listening to Lester's numerous media interviews, it's clear his goal this year is to bolster the passing game. I think this is something that has stuck in his craw since getting here. And now that he finally has QBs who have been in his system for more than a year, he wants to take that next step. Not to mention some actual receiving threats too. If the right guy is chosen, or if one of them comes into their own, Lester could really break this offense open like he's wanted to. He's cited he has a book full of plays he's yet to touch because we haven't had the personnel to pull them off, now we do, and he's been working on it all year.