By all accounts Keenum has made great strides. And I think he has a little bit of an "it" factor that TJ lacks in my view. He might even have more upside - TBD.
Having said that, he has to pass not one, but two guys with real NFL game experience, one of whom has playoff experience.
In my mind, Case has to not play even, or play a little better. He has to be clearly head and shoulders above TJ to be named #2. It has to be so obvious that Kubes has no choice.
To put it another way. it's a big game and the playoffs are on the line. Schaub just got sacked. It's 17 for the opponent, 10 for the Texans. There is 8 minutes left in the 4th quarter. Plenty of time. Looks like Schaub might be out the rest of the game, as he's limping to the sideline. Time to bring in your backup.
Now, do you want a guy there that's never taken a single NFL snap, or do you want the guy that led the team to the playoffs and was the starting QB in a playoff game?
If you answered the guy with no experience, then...