Worst underperformer, pitcher: Jon Lester
He's allowing more than a hit per inning, something he hasn't done since his rookie season, 2006. His strikeout rate is his lowest since 2008. He has the highest career winning percentage among all active pitchers, but a losing record this year. He's supposed to be the ace, the Red Sox' answer to CC Sabathia and David Price, but right now he's not even the answer to Ivan Nova and Jeremy Hellickson. And he seems downright miserable. A sure-thing has turned into an enigma. What's going on here, Jon Lester?