Based on my review of the current roster, I don't think we have a concern of losing someone we care a heck of a lot about.
However, we may have a problem with the 40/70 rule (two forwards and one defenseman must be exposed that played either 40 NHL games in 2016-2017 or 70 NHL games between the previous two seasons... and that player must be under contract for 2017-2018).
As of right now I only see a few forwards we have under contract who could fullfil that requirement (assuming we want to protect Kadri, JvR, Komarov, and Brown, plus Stamkos should he sign here):
Lupul - but he needs to play in 24 games this season and he needs to waive his NTC
Bozak - but I'd much rather trade him- I think he can net a 2nd round pick
The following players aren't under contract in '17-'18, so signing them to an extension just to expose them might be the best course of action:
Laich
Froese (needs 14 gp to qualify for 70 in 2 as well)
Michalek (needs 25 gp to qualify for 70 in 2 as well)
Greening (needs 39 gp to qualify for 70 in 2 as well)
Holland (assuming we keep him... might as well sign him to a 2 year deal now)
I don't see Leipsic playing enough NHL games to qualify- and he'd need a contract extension to boot.
On defense:
Protect: Rielly, Gardiner
Expires, so not eligible (unless we sign him to an extension): Hunwick
I see us most likely protecting Carrick, who is an RFA at the end of next season- so even if we choose not to protect him, we need him extended to qualify
That means, between Marincin, Corrado, and Harrington, who are all RFA's this offseason, at least one of them needs to be under contract for '17-'18 and play the required number of NHL games this upcoming season. (Marincin needs 5 NHL games to hit 70 in 2, Corrado needs 31 NHL games to hit 70 in 2, and Harrington would need 40 NHL games this season)
Anyways, I bring this up because there will be a lot of consideration management needs to do with their assets. Selling off players at the deadline might make it tougher to reach this requirement. They may need to make trades just to acquire players to meet the requirement. It will be an interesting to see what juggling happens in preparation for the expansion draft (and not just for the Leafs).