I probably should know this, but I don't. And searched the archives and didn't see anything.
Is there a way to retroactively DL someone in the majors?
i.e. If someone gets hurt for 15 days, but you keep them active for the first 10 days, then due to other factors need to DL-15 them on day 10 of their injury. Are they eligible to come off the DL after 5 more days or not until the full 15?
I believe in real life you can retro DL folks back to the date when they first missed time due to injury.