Thanks. That's what I had thought as well, but Beckett shows no difference between actual players (I'm sure Beckett isn't always the go-to for accurate checklists). However, after comparing them more closely, there are some differences in spelling.
Cal Ripken Jr.
Cal Ripken Jr
If this is indeed the difference, I have the 1988. Does anyone have one with the 1989 spelling of these players?