Recommendations for Questionable and Doubtful Players

I'm in my first week. Hoping someone with an extra week under his belt might have some advice.

After two games, I have:

QB - Andrew Luck (B0) - questionable
HB - Isaiah Crowell (B2) - doubtful
FB/BB - Vernon Davis (A0) - doubtful

So, do I leave them in the starting lineup and take my chances or try to reduce their usage by starting others?

Subs would be:

QB - Nick Foles (F12)
HB - either Darren Sproles (D0) or Ty Montgomery (D0)
FB/BB - either Kyle Juszczyk (F3) or Blake Bell (F13)

Given that Luck and Davis both have a "0" injury rating, I guess the worst that happens if I leave them in the starting lineup is they miss tonight's game and are back for tomorrow. Crowell is a bigger question: Given the "2" injury rating, is there a bigger risk of him missing two more games if he plays when doubtful than if he plays when he has neither a questionable nor a doubtful rating? My guess is that the fatigue settings function separately from the injury settings. (Programming them separately seems easier than programming them so they interrelate.)

Just thought I would check if someone with a week-plus of playing under his belt had an opinion.

Sub out hurt or overused players (any form of beat up)...
Always.

Much less chance of long term or season ending injuries.

Seems to me the overusage controls were not thought out very well.

Why do WRs and TEs have overusage at all? There is nothing we can do to regulate their usage. Even calling a minimal number of pass plays does not guarantee that your "overused" receiver will not catch too many of the attempts. Let the game engine regulate overusage for these players.

Also, STRAT does not seem to have considered that some stats are based on 12 & 14 game seasons. On one team, I have Pete Pihos (TE). After two games he had 7 catches and was listed doubtful. In real life, he had only 55 catches but in a 12 game season.

Just thought I would update that all three of the players I mention played game 3 without incident. In game 4, neither Luck nor Crowell played (I won anyway), so both are off the questionable/doubtful list for game 5. (Foles, my backup QB, is listed as doubtful after starting one game.) Davis is now listed as doubtful for the third straight game. I think the way to go is to leave players in your lineup and take your chances.