It's just such a tough injury, and rehab is no joke! I was 20 when I did mine and in great shape, but it still took 10 months before I was 100%. Although, I bet he will have a little better facilities than I did. Here's the quote from UT's trainer:
"We are hopeful Richie will be able to return for at least part of if not all of the 2005 season," UT head athletic trainer Keith Clements said. "However, most ACL rehabs take nine months on average. There may be some dynamics within Richie's situation, if the damage is limited to just the ACL, so that he possibly could return earlier rather than later."