The additions of Marcus Johansson and Charlie Coyle at the trade deadline gave Cassidy plenty of options when it comes to line combinations. But with Johansson and David Pastrnak both missing significant time since the deadline due to injury, Cassidy's ability to find the right permutations was hampered.
Now, with both players back in the lineup, Cassidy is doing his best to get a look at different trios. That shuffling began on Wednesday night against the Rangers, with Pastrnak sliding down to play with David Krejci and Johansson playing alongside Coyle.
The mixing and matching continued at Friday's practice with Cassidy placing Johansson on the B's top line with Brad Marchand and Patrice Bergeron.
"He's got playmaking ability, finishing ability. We haven't seen the best of Marcus yet for obvious reasons. He's been moved around, he's been injured, and we just tried him there today," Cassidy said of Johansson, who missed 10 games with a lung contusion before returning against the Rangers on Wednesday.
Pastrnak has played with DeBrusk and Krejci in limited instances over the past two years and had a strong performance alongside them in Wednesday's win over New York.
"Obviously Pasta did a nice job with Krejci and DeBrusk," said Cassidy. "It's something we talked about doing for a long time this year. I always found that Danton [Heinen] probably does his best work on that third line, down in the lineup.
"[Marcus] is on his off side, which we're still not sure that's ideal. But someone does have to play their off side, unless we start messing with our fourth line and I don't think we're gonna do that."