I've got my issue figured out.

I create my lineup with the starters that I want and with the
depth chart as follows:

Hoak 3b
Wills ss
Smith c ... Berra 1%, McCardell 0%
Aaron rf
Berra lf ... Callison 1%
Crowe 1b
Throneberry cf
Mazeroski 2b

If Smith gets hurt, the CM will start Berra at catcher until Smith is healthy and replace Berra in leftfield with Callison. I'm guessing that this is due to the catcher position being filled first by the CM so Berra is already assigned the catcher duties when the CM chooses the starting leftfielder. I think McCardell will be inserted at catcher for the remainder of the game when Smith is injured.

I expect that this is because of the hierarchy that the CM uses when assigning starting positions. (See the thread on the CM playing the same 3 players vs LHP or RHP but putting them in different positions.) We should be able to figure out the positional hierarchy without too much trouble but I haven't gone there yet.

Doug