Going against the grain here, but were I Keefe, I'd be thinking about using Nylander on the PK. While we've all seen his lackadaisical efforts over the years, his past 10 games or so have been, perhaps, his best ever. He's been effective at back checking, his skating we know, he can steal pucks with the best of them, I've even seen him throw the odd bodycheck

and of the C's Keefe is using on the PK, only Spezza (get off as soon as you can after the FO) has a winning percentage on the dot. Spezza, at 58.1% has been excellent in that regard. Willy is rocking a 57.1%, a solid 17% jump up from Kerfoot's work on the dot, up over 13% over Engvall's success rate, and a booming 25% better than Zach. Marner and Mykheyev are a combined 100%, but with 6 FO between them...
At just under 16.5 min TOI, using him on the PK certainly wouldn't hurt him. It would also take some of the strain Marner is experiencing playing 22.38 each night, with almost 2 min/ on the PK. Keefe has said that motivation is sometimes a problem for Nylander. We saw the positive impact benching him in the 3rd period a while back had on his play. Would a carrot now help? I believe he has the skills, can he be cajoled into offering the effort to become an effective PKer? Does the added responsibility make him a better player? I'd like to find out.