There is a simple reason as to why this will not happen this season...
He takes up too much cap room to let go.
Usually this is a bad thing, however, for the Chiefs and their current salary cap situation they are simply too close to the NFL's floor requirement to let go of Damion McIntosh's six year $18 Million contract. He's just too valuable (cap wise) to let go.
Take a look back at Primetime's article pertaining to the Salary Cap situation nearly a month ago and the affect of the Matt Cassel extension. We were still around $30 Million under the cap and needed to spend (by his estimations) another $13 million to meet the Salary Cap Floor.
The following figures are taken from the wikipedia article on the Salary Cap:
In 2009, the cap will be $128 million per team, while the floor will be 87.6% of the cap, using the formula provided in the league's collective bargaining agreement, the floor will be $112.1 million.
If that be the case our payroll prior to the Matt Cassel deal was around $98 million. The transactions that have succeeded the Cassel deal have been the release/waiver of Weston Dacus, Ingle Martin, Edwin Harrison, Tony Curtis, Tanner Purdum, and Jeff Webb, in favor for Tyson Jackson, Matt Gutierrez, Amani Toomer, Vince Redd, Thomas Gafford, and Ashley Lelie, correspondingly.
The only transaction that created a major flux within the payroll was Jackson's 5 year, $57 Million contract with $31 Million guaranteed. Last year, Glenn Dorsey's 2008 salary was $6,933,250 and his contract was 5 year, $51 million with $22 million guaranteed. Therefore, Jackson's 2009 salary will be in the ballpark of $7.5-$9 Million (I don't know how to calculate the exact number). Hence, the Chiefs will be remain around $6 Million dollars under the floor (give or take a million dollars or so for Amani Toomer's deal).
Taking McIntosh's $2.5 Million dollar salary just doesn't seem possible if the Chiefs indeed remain under the floor. Surely his ability does not warrant his salary but that's not currently what is most important. The importance lies within the space consumed by his salary, rather than the space taken up by his rotund belly