Adams was due a $2.5 million roster bonus and Free's base is below $1 million - Jones wouldn't have done it if he didn't think he had equal or better options. Adams just wouldn't fit on the team as a high-priced backup.
The urgency Jones spoke of when announcing Wade Phillips' two-year contract extension means a deeper playoff run is expected. You don't see Jones cutting Keith Brooking and starting Jason Williams, who's still learning the 3-4 defense, just to save a little change. It comes down to cost and readiness.
There's a delicate balance in simultaneously getting younger and getting better. Austin, Jenkins and Spencer took them farther with larger roles. Free's turn could be next.
Next man up.