Miguel doesn't like to acknowledge the existance of a cap hell.
Mannings contract becomes a problem in 2008 - he has one more $10 roster bonus against negligable salary due next season that can be converted to signing bonus and prorated (as they were able to do with this years $9M roster bonus once the new CBA was enacted). Trouble is all that prorated money is being pushed forward into years that include double digit salary and part of the initial $34.5M signing bonus. Unless they redo his deal (and that will mean an additional signing bonus and 5 years to prorate that into when he's 35+) they are facing down cap numbers in the $17-21M range starting in 2008. With a redo they will likely skate along until dead cap time, when Peyton's contract outlives his career. They face a similar scenario with Marvin.
Right now they can probably squeeze Mathis in - they were about $7+M under at last check. Can't likely fit him and Freeney in though. Freeney's cap number could drop (it's $5M almost all salary this year) but if he wants to be the highest paid DE (or as Pastabelli reported last week the highest paid player period...LOL) that would be tough to pull off without boatloads of (you guessed it) pro-ratable bonus money .
They could always franchise Freeney, but it will cost around $9M on the cap next season for a DE and if he really wants that kind of money long term he might demand a trade rather than risk playing for a year under a tag. They also will have Cato June to deal with since he is an RFA this year.
A financial factor to keep in mind for them is the new stadium opening in 2008 will generate far more cash flow - it's been tough for Irsay to come up with all the bonus money he spends (in part to artificially keep his cap numbers low). He had to sell personal assets (a rock and roll memorabelia collection) to fund Peyton's $34.5M in 2004 but he got a $30M buyout on the lease of the RCA Dome this year as part of the deal to let the Indy taxpayers build him a new place - although that was quickly gobbled up by Manning and Harrison's roster bonuses ($19M) and Wayne's signing bonus ($12.5M). However, he won't have any windfall I can forsee in 2007, and the cap will likely only go up closer to the usual 5-6%. So if Freeney is really looking for a QB-esque deal the Colts may have neither the cash or the cap to accommodate him. Remember they also added Corey Simon last season and his deal averages $6M - and had an $8M option for 2006 which I can only assume they exercised (...and likely converted and pro rated).
Adam actually saved them over a million this year compared to their cap hit for Vanderjerk last season, not to mention the cost of the dedicated KO specialist they carried because Vandy couldn't multi-task.
Still all these chickens will come home to roost eventually, and if the Colts should fall off appreciable, even in their now accustomed regular season dominance, it could effect ticket sales for the 2008 grand opening of the new Lubradome to boot.