I know this has been discussed before but I can't find the thread. How many innings pitched should a major league pitcher have during spring training? How about at bats for a major league hitter? I know it is important not to overwork a pitcher but does it matter for a hitter?

There are many opinions.  I like my pitchers to get three appearances.   I'll set SP at 40-50 pitches and RP at 20-25.  How many innings they get is up to them.

I want BL players to get 20 AB and my top prospects to get 30+.   Fill in the rest of the AB with 2nd level prospects.

After a big injury in ST to a pitcher in one of my worlds, I decided to gamble on no ST innings or at bats for my ML players and top prospect (pretty barren minors).

The results?  No ratings increase  (they are all 27+ anyway) or decrease for my ML players and a ratings increase for my prospect, even though he never appeared in a ST game.  Many of the Low A fodder that I used also got bumps.

You'll probably notice that players who weren't even invited got bumps.    But playing time does matter, at least it did on the few players I tested, for development.

For complete disclosure, the "test" subjects weren't real prospects so I don't know how much development they would have gotten had they not played but they did develop more than similar players who weren't invited.