I'm not subscribing to any of the below but I can do an out of body thing and tell you why you won't see Mallett/Savage until late in the season, if then...
hear me out:
As long as we're not mathematically eliminated from the playoffs with Fitzpatrick at QB, O'Brien has no reason to change QBs.
The only way we'll see Mallet/Savage this season is if - and only if - Fitzpatrick's play starts to definitively cost us games.
Right now we have a winning record. Even if we lose tonight, we'll still be at .500. Compared to last season when we were 2-4 after six games, that's an improvement.
Coaches don't mess with what they think is working; even if it's only half-assed working....
ESPECIALLY for an unknown commodity.
And as frustratingly unsatisfying as his play has been, Fitz. is. a. KNOWN.
Coaches can manage a substandard known.
They do it all the time.
They "hide" LBs who can't cover.
The help out O-line guys who suck at pass blocking.
And with a quasi-healthy Foster and an improving Blue, O'Brien can run the ball 50-60-70% of the time and only call "safe" passes and "hide" Fitz. Hell, that's how we won the first two games. And thanks to our defense, we haven't had to play serious catchup (say, like the Browns just did)
Now, you guys want O'Brien to give up a known -albeit a sucky known but a manageable known for a complete unknown.
Bottom line: Unless Fitz goes down with injury or the possibility of playoffs is eliminated, a QB change is not gonna happen.