The Astros would be quite happy if he accepted their $3.1M offer and they didn't get the comp pick. It's not just about the time frame, it's also about the risk involved. TJ surgery isn't a cure all. Not everyone comes back from it where they were. A lot of guys do, but not all of them, so there's risk there.
It will be very interesting to see how it works out if he decides to try and go the Barret Loux route. I guess at that point we will see just how rational the Astros were being, assuming it gets that far.