Agreed, Rodgers retiring before the end of his current contract will definitely result in the Packers having to make some moves to make it work with the cap.
I'll give it a try to explain dead money counting against the cap to you
It accrues when a player has received a signing bonus is released, traded or retires before the end of his current. In addition any future guarantees will result in dead money counting against the cap if the player is released before earning them.
The amount is calculated as follows. The signing bonus is prorated over the length of the contract (a maximum of five yesrs though). For example, Rodgers received a $40.8 million signing bonus this season, which will count $8.16 million against the Packers cap in each of the next five years. But, if Rodgers ends up retiring before that the rest of the prorated portion will count against the Packers cap the following season. Once again, for example, if Rodgers retires after the 2022 season there would be four years of the prorated signing bonus left, resulting in $32.64 million of dead money counting against the Packers cap in '23.
That's common with most contracts in the NFL in some way. But here is where it gets tricky with Rodgers contract.
If he decides to play in 2023 he's due a $57.3 milion option bonus for that year. The CBA allows that to be handled like a signing bonus regarding the cap, resulting in it being prorated over the four remaining years of his contract for a cap hit of $14.575 million each season.
Once again, if he retires after the 2023 season the remaining portion of the prorated signing bonus he received this offseason (at that point three years at $8.16 million for a total of $24.48 million) as well as of the option bonus he would have received in 2023 (three years at $14.575 million for a combined $43.725 million) would result in a total of $68.205 million of dead money counting against the Packers cap in 2024.
To make things even more interesting there's another option bonus of $47 million waiting for him if he plays in 2024 as well. That one will be prorated over the remaining three years once again, resulting in even more dead money counting against the Packerd cap in 2025 if Rodgers retires after the '24 season.
Other posters already pointed out how the fifth year option works. At more than $20 million for Love next offseason it would be a terrible decision for the Packers to exercise it on him.
Too bad Gutekunst didn't think of that during the first round of the 2020 draft.
You need to understand that the NBA having a soft cap and the MLB not having one at all is the reason for that.