MAVS NEWS:

[F Gump]

In theory, IF Dallas wanted to activate 2 of these said players, couldn't they have applied for a medical exception for Irving? It would NOT affect the Hard Cap but it would create an extra roster slot if they have enough room under the Apron... Of course they should have applied for the Hardship WHEN Kyrie had surgery, but again that comes down to proper GM procedural maneuvers. Good Lord I miss Dennis Lindsey

 
No. (These various rules often get confused.)

In mentioning Kyrie, you seem to be citing the Disabled Player Exception rule, which allows a team a Cap Exception (ie, permission to exceed the cap spending limit of ~$141M) to have some spending freedom to sign a player to replace a player who is out for the season. If granted, you get a signing exception for half the salary of the injured player, with a regular contract that can be for multiple years if you wish.

But this is not a permission to exceed the hard cap (there is NO permission for that, ever), nor is it a roster limit exception (to the 15-man maximum), and it must be applied for by Jan 15.

There is a separate, general Hardship Exception to the 15-man roster limit, but it is not tied to a specific player's injury. It is available when a team has 4-or-more players on the 15-man roster who are unavailable to play for an extended period (each of the 4 players must have been out for 3 or more consecutive games, at the point at which a hardship player is added and used) all at the same time. It allows adding player 16 (or more, if the number of such unavailable players is greater than 4) until there are 12 or more who can suit up. But the Mavs have been ineligible to apply for that, since they haven't even been using all the roster spots they have.

It is this Hardship Exception that, in general, could theoretically make it legal for them to use their leftover sliver of money under the hard cap and sign a 16th player for the last day of the season, after first signing a 15th for the last 2 games. But such a signing could not including anything beyond rest-of-season contract, and would not allow any post-season play (only the 15-man roster can play post-season games).

HOWEVER - It is very iffy as to whether they could even qualify for a hardship exception at that point. It takes 4 players who have been out for 3+ games. But with the return of Gaff and Lively looming, it looks like they will only have 3 (Kyrie and OMax are done for the season, and Exum shouldn't be back yet by that point).