Ah, I see now. It just happened to Biggio who went from 1-6 days to 3-4 weeks, with 23 days days list time left. I wasn't sure if the game has like reassessments or rehab setbacks to sometimes add time for realism.
Reading up on how the injured list works, you can basically keep a player on the 10-Day for over 60-Days so long as you keep putting them back on it, which looks to be the best option for 1-2 month injuries. Maybe the game that clear back when I started my franchise like 6 months ago...Oh well. I'm still playing good baseball without him. I can survive the next 17ish games. Thanks!