Summary
Gay has always been a good scorer. His size allows him to get shots off, and his ability to hit contested shots can be helpful when the offense stalls or on second units that are lacking offensive creation. Gay didn't have the best year though, shooting below-average from midrange shooter for the first time since his rookie year, according to Cleaning the Glass. He's not a great threat from three, but he shoots a decent percentage to the point defenses generally respect him.
 
He doesn't have the explosiveness that he did back in his prime, and that has really shown this season with his low percentage on shots at the rim. Gay will be 35 this summer, and I don't expect him to get any long-term offers. He should have some interest though as a versatile backup forward that can still score, similar to what Carmelo Anthony has provided to Portland over the last couple seasons.
 
Cap Considerations
Gay will be an unrestricted free agent with full Bird rights. As his cap hold ($21.8 million) exceeds the salary he will get in free agency, his cap hold is not really relevant. If the Spurs re-sign Gay, his cap hold will be replaced by his starting salary, and the Spurs may still have some cap space available depending on his salary and what happens with their other free agents. If Gay is brought back by the Spurs on a multi-year contract, they could benefit from frontloading his contract, as it could give them additional flexibility in the future.
 
Other teams will have multiple ways to sign Gay as even teams without cap space could possibly use either of the Non-Taxpayer MLE, Taxpayer MLE, or possibly even the Room MLE to sign him.