Their 4th line and Sam Bennett were the only forwards to show up with a pulse against Colorado and he was the only physical presence on that line.
Flames probably let him go because they're trying to max their cap spending on their top 6 and hoping to get by with league min 4th liners where they can. It's what the caps did last year with Dowd, Stephenson and DSP costing like 2.5 mil total. Ultimately didn't pay off and the 4th line was a nonfactor whereas the year before it was very clutch in a cup run.
Capitals strategy this year is to spend more cap space on solid depth players since their top 6 and top 4 are all locked in and they're not looking to bring in any high salary impact players and play them on the 3rd line/bottom 3 on D. So Hagelin, Panik, Hathaway, Gudas and Leipsic to have a qualified forward at every role to tilt the ice over 7 games even if he won't set the world on fire. The flip side is if their top 6 doesn't show up for a round they probably won't have the bottom 6 carry the scoring enough to make up for it