Coming off the Dodgers series, there are 13 games left in the season. I think the best way to get the team ready for the playoffs is to manage like they’ve already begun. The first priority is health. Play the guys coming off injury (Jayson Werth, Trea Turner, Michael Taylor, and eventually (hopefully) Bryce Harper), and give the guys who’ve been playing every day the occasional day off. And then pinch-hit, pinch-run, and defensively substitute like you would in October.
Set the lineup based on the team’s health, then use whatever bench and bullpen options you have that day to win the game. Make the games matter to keep the team sharp. It’s also a great way to sort out the bench and back of the bullpen to pinpoint the most effective playoff roster.