...then tore the ACL at the combine? The player would have burned the college bridge behind him, and thrown away his NFL future. He better have health insurance because neither his former college nor any NFL team will pay for his surgery & rehab at this point.

Now if that player was thinking about the NFL while preparing for a bowl, the school picks up his surgery & rehab. He will miss the combine, but he still has the option of returning for another year to get his knee back to 100% before heading to the NFL.

Now if it's a senior playing one more bowl before the NFL, the college picks up the surgery and rehab before he leaves...hopefully with bachelors and masters degrees so he has multiple future options outside of just the NFL.