Phil Kessel had 12 goals and 42 points on the power play last year. Phil was a poor five-on-five player down the stretch, but is still a great PP specialist.
That being said, the Penguins PP will be fine next year. In the two years prior to Kessel's arrival, the Penguins finished 1st and 2nd in the league on the man advantage.
Kris Letang can boom one-timers from the left half wall. Justin Schultz can man the point with Evgeni Malkin. Hey, how about 40-goal-scorer Jake Guentzel in the slot/down low?
The Penguins gave up an embarrassing 15 shorthanded goals last year. With Schultz and Letang on the ice, I'm betting they don't come close to repeating that disaster.
Even without Phil Kessel the Penguins power play will still be good.