This quality-of-life post courtesy of Reddit user FancyKillerWales is a nice to have and something I was actually trying to find before stumbling on it. If you’re losing your mind trying to get team affinity points via Showdown, knocking out a lot of the smaller Diamond Dynasty team affinity missions for teams can push you towards your goal as well.
All of this info is technically available in-game, but you have to dig around to find it, which is annoying to do when you just want to assemble a roster to cover a bunch of these missions all at once. So, instead, FancyKillerWales put it together in a handy little list you can bookmark and keep on hand when trying to scrounge together those last crucial Team Affinity points. The list includes all 30 MLB teams, so you’re totally covered.
Completing any one of these missions will net you five team affinity points for the respective team.