I'm having a hard time with this logic. If he was 28, sure, who cares what he did at 25.
An aging curve is a real thing. His peripherals getting worse is a pattern likely influenced by his age. You can use this to help predict how he is likely to perform this year.
I know you know this, so I'm confused.
I don't really care that he gave up runs last night, I worry that a guy in decline is again going to be given a long leash in critical situations and it will cost the team wins. I thought this a month ago and if he converts the next 3 saves perfectly, I'll feel the same.