Instead of earning $20 million in fully guaranteed base salaries in 2013 and 2014, Manning received a $10 million salary advance and his base salaries in 2013 and 2014 have been lowered to $15 million in each season. The $10 million salary advance is treated like a signing bonus and will be prorated over the next four seasons, reducing Manning's cap number from $20 million to $17.5 million in both 2013 and 2014.
The nature of the beast also means that Manning's cap number will rise from 19 million to 21.5 million in 2015 and 2016. If for some reason the Broncos and Manning parted ways before then, his cap hit would be 2.5 million in dead money each season.
Overall I like the move. It provides the Broncos some cap relief the next two seasons when the Broncos have a slew of freeagents to resign. It also isn't a big enough restructure that the Broncos will be handicapped by it in future seasons.
According to the article, the Broncos now have approximately 9.9 million in cap space this year.
EDIT 5:13 PM MDT
According to Mike Florio Manning's contract didn't change, the league's interpretation of it did:
Manning’s original deal contains a $5 million salary advance of 2013 pay and a $5 million salary advance for 2014 compensation. The league initially didn’t treat the advances as signing bonuses, which gets prorated.
The new deal, which didn’t change the payments or the structure of the deal, prompted the NFL to treat the payments differently. As a result, the league has applied the $10 million in salary advances in $2.5 million equal chunks over the final four years of the contract. The cap numbers for 2013 and 2014 have dropped from $20 million to $17.5 million, and the cap numbers for 2015 and 2016 have jumped from $19 million to $21.5 million.
Semantics, Semantics. Bottom line, we still have that extra 2.5 million this year and next that I reported originally.