If we are up 2-1, it would be incredibly, incredibly stupid to start Stras on short rest. If he doesn't do well, it's basically series over. You go with Roark. If he loses oh well, I'll take Stras any day of the week over Hendricks.
If you go with Roark, you lose. That means Game 5 against a pitcher who currently rents a cattle ranch worth of space in Nationals' hitters. Under no circumstance can you go to a Game 5. Stras can give you five innings. Albers, Madson, and Perez can get you to the 8th