Spring training serves several different roles.
- It allows players more time for development with the big league coaching staff.
- It allows the owner to get a better feel for how HBD works and how his players fare against tougher competition.
- It's definitely wise not to play your starters more than half a game because they will build up fatigue as the season progresses. Also, you'll want to make sure your pitch counts are lower during Spring Training so that your starting pitchers aren't going 7 innings (the recommendations do this automatically during spring training).
- It's very similar to real life spring training in that you want your prospects to play more and you can also use the time to evaluate non-roster invitees and fringe-type players to see if they are worth keeping on the big league club or sending to the minors.
- Spring training is also a good time to showcase potential trade bait, determine shortcomings for trade proposals, etc. At some point in the future, we'll be adding a rust-like component to the game so that if players don't get enough PT in spring training, they'll start off slow but it's not in the game yet.