Q and D injury status

What happens with Q? What happens with D? What happens when you have two players at a position and both are A or both are D? How long does the status last?

Q and D occur when a QB is on pace to throw more passes than real life, a running back is on pace to run more than real life, or a receiver is on pace to catch more passes than real life. It doesn't seem to affect performance (but that is hard to prove) but it does affect playing time. If all players are both Q or both D the player with the lower amount of overusage will get more reps. If a player has an injury then they are out. I don't know what will happen if you have both QBs or TEs injured.