There is one stunning statistic with regards to McDonald's demise. On June 21, 2012, James McDonald threw 120 pitches in a complete game gem to reduce his ERA to 2.19. In McDonald's remaining games last year he put up an ERA of 6.5.
He is clearly messed up this year. I don't know what happened to him but I suspect that his overuse during the first half last season contributed to his collapse. He has never had much stamina.