That's a good point about the 3rd year and us having full Bird rights.
I am pretty sure you can't, but is there any way you can have both a team and/or player option for the 3rd year?
Say he picks up the option for x amount of dollars, and if not the team can decide to pick it up for something greater than x amount. If the team or him decide not to pick up the option he's able to walk. This could ensure himself of an extra year of getting paid in case his knees give out and ensure the Spurs get his Bird rights if they pick up the option.
Reading my post again....makes me think I should stick to lurking.