No you wouldn't. They are comfortably above the cap floor right now with Stoner and Haula healthy. With Haula and Stoner healthy, I think the Knights are at $60.23 million with 13 forwards, 11 D and 2 goalies. They obviously have to trade some of their defensemen, so that could change if they move like Garrison, but they're comfortably above the cap floor, assuming they move like Reinhart and Merrill from their defense.
It also becomes less of an issue if it happens later in the season, like in December or January, or if they take back a contract like Hagelin's.