I apologize if this has been asked, I tried googling around didn't help and I don't know how to search the forum.

Let's say the Oilers trade for a player with a $2M cap hit, and then Sekera suddenly gets cleared a week later. Do they have to immediately make moves to become cap compliant?

Yes, they do

And since I assume teams are under no obligation to help them out in this spot, they'd be pretty screwed?

They'd be in a tough situation if they filled the roster position with a high cap hit player.

Generally they know whether or not a player is likely to return this season, and plan accordingly.

I just wanted to end an argument with someone who was suggesting the Leafs could/should trade Connor Brown to the Oilers because they have cap space from the LTIR relief for Sekera, and wanted to point out how stupid it would be for Edmonton to put themselves in that spot. Thanks!