Way more that goes into it.
1. Health
2. Wear and tear
3. He’s now going into free agency fully healthy with less wear and tear, and he’s absolutely going to break the bank.
4. If he gets hurt this year while having another year of wear and tear on his body, his value plummets. Especially as a soon to be 27 year old running back. 14 mil would be absolutely nothing compared to the value he would lose if he got hurt.