Because PATFO are naive enough to keep an injured player if that's the verbal agreement?
It obviously allows him to keep his options open, but I don't think it's a foregone conclusion he'll surely leave before the deadline.
As I said, there aren't many top contenders that would be interested and if Spurs are close to .500 in February, there's no point in leaving for another first round exit team.
I'd say that him staying with the Spurs for two seasons is as likely as him leaving before deadline.
Starter this season, backup the next and then joins the coaching staff if he's interested.
He seems like someone too invested in basketball to not become a coach. Spurs are his by far the best option if he wants to take that route.