Cassidy should give Kase some more time on the top line. I certainly don't see him individually as a first line talent but he's clearly got some skills and can hang with the top guys, and if anyone can help him re-find his touch it's Bergeron.
Stick Pasta on the 2nd line with Krej as they did against the Flyers and put Bjork or Ritchie on the left, and hopefully that gives you 2 lines that pack a proper scoring threat, plus the Coyle-DeBrusk combo should only continue to get better.
Start with that, and Cassidy can always go back to the 'classic' top line combo if there is need at any point during a game.