FLEX AND DP

[Stat-Man]

Originally posted by DaveASA/FED
So #1 is DP #2 is Flex, 1st inning 2 misses 2 balls at 1st so you replace her with 1. 2 now has left the game as her only thing she did was play defense and now she is not doing that. DP has not done anything but taken over defense for flex. 2nd inning you left #2 try again, this has burnt her one reentry, if you replace her with the DP again then #2 is done for the game. Now you can bring #3 (a legal substitute) in for #2 in the flex position, but #2 can not reenter twice. Note, DP #1 still has not had any change in there status as they have never left the game.

If the DP plays defense for the FLEX, why does the FLEX have to burn a reentry if they come back on defense?

I can think of a scenario where that may be true, but in this scenario, I feel like I'm missing something.