Hopefully for your sake and others with the same goal in mind they allow this option.
I'm only skeptical because I'm pretty sure the'll tout this feature as one that allows you to actually take your player through an entire career and try to reach milestones in a reasonable amount of time (games take 5-10 minutes or less). If you play every single play of the game, you're not gaining the full advantage of moving quickly through a career compared to just creating a player and playing franchise (I guess you would save time on the offensive side assuming you only have to play when up to bat or on base).