You seem to be able to download the data from MLB's gameday service. However, it can only be used for non-commercial purposes (likely the same for any of the free/cheap sources). There's two ways to get it. This explains the older method:
http://www.michealwillard.com/mlbam_api/
So for example, here's yesterday's game:
http://gd2.mlb.com/components/game/mlb/year_2019/month_03/day_28/gid_2019_03_28_detmlb_tormlb_1/
And here's the full game data (It looks like the spin rates this year aren't displayed here for some reason).
http://gd2.mlb.com/components/game/mlb/year_2019/month_03/day_28/gid_2019_03_28_detmlb_tormlb_1/inning/inning_all.xml
And you seem to be able to access a more modern api as well (the JSON is a lot easier to work with directly):
https://statsapi.mlb.com/api/v1/schedule?sportId=1&date=03/28/2019
The live data section has pitchs and information, but I don't see it listed for yesterday's games for some reason. Here's a random game from last year:
https://statsapi.mlb.com/api/v1/game/529942/feed/live
Do keep in mind that the data is NOT scrubbed. This means that once in a while you get duplicate events listed, events out of order, etc. It's a nightmare to work with if you care about 100% accuracy, but extremely useful if you only care about it being right 99% of the time.
Atkins has said they're below their budget for the season, and I'm pretty sure he suggested they'd be looking to make strategic adds as opportunities arose.