and players ratings don't change overnight, but my 33-year-old setup reliever (a career closer) was a 79 (out of 80) on Opening Day and is a 30 on April 25th. Sure glad I signed him to a two-year extension based on the fact that stuff like this is impossible...
Again, the fact is I've been watching multiple players of all different ages do this every year. (Thankfully, I traded the 33-year-old first baseman the year before he went from a 70 to a 21. Not so lucky with the reliever.)