Kunitz has 2 points in 9 games this postseason, while playing with Sid and Geno. I think it's the lowest on the team. If he's not killing shifts, he doesn't finish chances, and at this point, I don't really expect him to.
Rust added energy and speed on that line yesterday, but he lacks good hands. Geno went beast mode, but playing him with Kunitz is a waste of energy.
I would throw Kunitz on the forth line with Cullen-Kuhn, if they refuse to sit him.
Bringing Sprong might be an option, but I doubt they would do it. I wish Bennet was healthy (lol, I know). I'd try Fehr or Sundqvist with Rust-Malkin, just to see if it would work better than with Kunitz.