Today the Leafs announced three injury updates. As noted above, Nick Robertson, currently on LTIR, will stay on LTIR and miss the rest of the season.

Mac Hollowell, currently in the AHL, will miss 12 weeks, which means he might be available for the playoffs with the Marlies.

TJ Brodie is not very badly hurt, and will only miss approximately one more week.

With Robertson done for the year, that makes it essentially impossible for the Leafs to not be in LTIR for the rest of the season. As discussed in this post:

Measuring the Leafs deadline salary cap space

The Leafs will only be able to add players between now and the deadline “dollar-for-dollar”. There will be no reason to wait to the last minute, since proration of the incoming player’s contract can’t happen in LTIR space.