Because teams at the deadline get more desperate for help, especially when injuries kick in and they're pushing up against whatever internal salary caps they have in place. Obviously this would also only happen if he pitches well in the first half, both in terms of advanced stats and actual results. Last year the advanced stats suggest he's a viable 5th starter. The actual results weren't quite as kind, and likely pushed his value down (granted front offices are getting better in that regard). Richard is (probably) better than Liriano when we traded him, albeit with less potential upside, and definitely cheaper.