I'm not advocating that he be pushed out because of his age. I'd be advocating the same thing if he was 28. He just can't perform up to standards. There just aren't enough garbage innings in a season to justify a spot for him as the team is fighting for a playoff spot. Middle relievers need to hold a game close to give the offense a chance to get back in the game. He can't serve that function anymore.
As for me being put out to pasture, if I couldn't do the job anymore, I wouldn't want to continue. In my job, there is no room for failures. I can't field issues at a .970 clip and expect to keep my job. Mistakes cost the company millions. If you make them, you are toast. That's the cold hard truth, and it doesn't matter if you are 30 or 50.