You don't know his situation, for all we know he prefers the money now (maybe he has family that needs help) and being set for life over being fiilthy rich in four years if he stays healthy and continues to produce. It's not irrational, a few million now may be worth a lot more than $50M five years from now that he'll just waste on a McMansion and expensive cars.
My advice to a potential client would be to play it safe and save your money on the first deal, gamble on the second deal.
For the Phillies it locks in an affordable starter for the indefinite future and makes him affordable as a 4th OF playing 400 PA a year if he does decline or develops a severe platoon split.
I'd also point out that the gravy days for sports are probably over, there are some ominious signs for ESPN as younger viewers don't want to pay for an increasingly expensive cable channel - without ESPN and local cable deals escalating, sports revenue may flat line - there's only so many advertising dollars and the internet is competing for them.
People who don't know economic history have a habit of escalating revenue streams indefinitely, but sports can't swallow the entire advertising expenditures, and ticket prices are maxed, as are luxury boxes - and don't think there's a pot of gold in subscribtion services - ask the music industry about that!