i had it work every time when i set as such:
to move musial to 1B to replace mccovey and then have rucker fill in in LF you have to set it as it reads.
on mccovey's check remove for def sub, then [b:819c907bf2]do not[/b:819c907bf2] check it on musial card (otherwise he would logically get replaced at any position he was at).
then set your def replacement #1 as musial - 1B.
then set your def replacement #2 as rucker - LF.
thankfully this is the one option of the game that was easy to figure out.
-steven