Iirc, if you retire you forfeit the remaining money on your contract (Adam LaRoche gave up something like $14 million remaining on his contract when he retired after the White Sox banned Drake LaRoche from their clubhouse) but if you are forced to retire due to career-ending injury you still get paid (which is why Chris Davis was paid his full contract by the O's). I assume Strasburg is the latter.
As for Strasburg, he put DC on the baseball map and won this franchise a World Series. Very simple.
THere was a tweet I saw about him negotiating. He can simply come in every year and be put on the IL. That's his right as a player.
