[Ataraxzy]

Cards in PT are varied and fun.

Cards in OOTP? ugh.

Have the game release special editions, legends, unsung heroes and so forth during the season. Let players collect them by doing stuff in game like 'steal a base', or 'modify a batting order' or something. Doesn't have to be (nor should it be) PT-like in terms of 'value' or whatever, just make the cards interesting, and have different sets available and a way, and reason to collect them.

Edit: just wanted to point out that baseball cards are as much a part of the game as blockbuster trades. They need some love. Desperately.