I think you are underestimating his value. A proven pitcher who is a lock to toss 180-200 innings and post an ERA in the mid to high 3s has quite a bit of value. Van Slyke is a nice player, but trading Yo should get a much better return. He does have a quite a bit of value. Its worth about $12-15 million for a year. Gallardo's FIP the past three years: 3.94, 3.89, 3.94. He has a distinct pattern. And Van Slyke was a monster last year to the tune of .297/.386/.524. He has 455 major league plate appearances and has the line of .261/.348/.476.