Freeney, who turned 32 in February, is entering the final year of a contract that will pay him $14.035 million -- which will be fully guaranteed as of 4 p.m. ET on Saturday -- in base salary, which is the second-highest in the NFL this season, trailing only Manning's $18 million salary with the Denver Broncos.
Freeney's $19.035 million cap number is the highest in the NFL and represents 15 percent of the $128.807 million in salary-cap space that first-year general manager Ryan Grigson has to work with this season.
"Oh, 35 percent of the time," Freeney said when asked how often he thinks about how 2012 is his contract year. "Yeah. Contract year, you know this could be it. If it is it, you want to cherish every moment you have still in this building and in this city, and hopefully you can get something done. So I would say 35 percent of the time.
"Not over half, you're thinking about everything else, but sometimes you reflect. I think when you get older, you start doing that a little bit more than when you're younger. When you're younger going into a contract year, it's not really a big deal. When you're older, it's kind of like, 'Well, this could be it. I don't know.' You don't know what's going to happen."
How Freeney adjusts to his switch from defensive end in a 4-3 system to an outside linebacker in coach Chuck Pagano's 3-4 defense is one the season's more intriguing subplots.
If he has another double-digit sack season, he could do quite well for himself on the free-agent market in 2013. One thing that's certain is that Freeney will not receive the franchise tag, which would cost the Colts 120 percent of Freeney's cap number, or $22.842 million next season.
Follow Brian McIntyre on Twitter @brian_mcintyre.