Rookies salaries are included in our salary cap as soon as they are drafted, but they are included at the minimum active list salary, which is roughly $405,000 this year. Clearly Fisher is going to exceed that by quite a bit.
There is no separate rookie salary pool, that is just minimum and maximum values which the team must/cannot exceed when signing their rookies.
http://www.overthecap.com/teamcap.ph...iefs&Year=2013
However, it looks like the Chiefs rolled over 14 million salary cap space from 2012 into 2013, so that would alleviate the problem, at least per Adam Teicher.