Team: 2017-18 Toronto Maple Leafs

Initial Creation Date: Oct. 6, 2017

Published: Oct. 6, 2017

Salary Cap Mode: Basic

Leafs Lineup against NYR after Marincin waived and buried in NHL and Rosen called up.
To simulate what the Leafs apparently did and what CF is now showing as far as remaining cap space and LTIR usage, I had to take a couple steps.
1. First I created the roster with Marincin and no Rosen (same as Leafs had in their first game).
2. Next, I used LTIR Pro Mode with Lupul to get the same cap space leftover that CF reported. (Some debate that Horton was the first one used because he was on LTIR in the offseason, but CF used Lupul and I agree because it is more effective by $50K and offseason LTIR does not necessarily transfer to in-season LTIR decisions as far as I understand.
3. Then bury Marincin in the AHL (cap savings of $1.025M).
4. Create a 'full impact' Calle Rosen player with a salary of $1.775M ($925K + 850K bonus).
5. Use Rookie mode to use Horton's $5.3M LTIR. This is because in-season, the remainder of an LTIR is still available for subsequent salary additions.
By doing these steps, we end up with an available cap space and unused LTIR of $4,550,000 which is what CF reported on it's updated LTIR summary today.

(The reason that Rosens $850K bonus had to be converted to salary is because that's how LTIR works when the LTIR player (Lupul or Horton) has no Perf. Bonus relief to provide because they did not have any when they went on LTIR. In that case, the P.B. has to be covered by the LTIR salary relief pool instead, so the PB effectively becomes salary as far as cap calculations go when using LTIR relief.)

If Aaltonen comes up as well in future, we will see even more cap and LTIR relief craziness.

This is my understanding and I'm sticking to it, at least for today. :p

A detail we may never be able to see confirmed:
I believe that when the Leafs brought up Rosen, there was an automatic transfer of $625K of his $850K ELC PB to a salary-equivalent cap hit due to the League rules on maximum ELC bonuses (limit is 7.5% of $75M cap). In this case, the excess of $625K would have 'taxed' as a cap hit immediately.
Now this doesn't really matter because both the $625K and the remainder $225K would both have to be included in the LTIR salary relief pool anyways, as explained above and in CF's LTIR FAQ.
So we'll probably never see this on paper...