I can think now that health and skills in basketball is really important so the team will value you.
That's the factors the management will see to determine your market value. With regards to Jeremy Lin i think injury is the one that is keeping him at bay while age is slowly betraying him. He got limited minutes or none at all during his stint with the Raptors because Lowry and Van Vleet are the priority in the rotation.
One more thing, his defense is not so appreciated by the management, Lowry and Van Vleet are both aggressive when it comes to defense and they both can shoot the ball well, who would expect that Van Vleet would be a big help for the Raptors in the Finals.