Honestly, you'regonna question Heyward's motivation? You can question many things about Jason, but I'm fairly sure there's less than a handful of players on the team who work harder than him. Think about the last time Jason dogged it down the line, or gave up on a ball,or done any number of things.
Not even what was being referenced in the quote. You think he walks on water because Fangraphs said "5.0 WAR." That gave him a free pass for hitting around BJ & Uggla levels during the 1st half.