Be patient yes, but be looking for his sinker in a specific half of the plate. If he throws it there on the first pitch, crush it. If he doesn't throw it there until the third pitch, then wait until the third pitch then crush it. Take his sliders or his sinkers at the edges or off the plate, but don't take pitches just to take pitches.
If he has trouble throwing his slider for strikes and the hitters are disciplined enough to lay off them, it can get ugly for him.