freeradius client configuration

Hi All,

I have configured the free radius client and server and both are are working
fine.
I just want to know, is this possible in freeradius client side to restrict
a particular user (Eg: root) to
do not send request to radius server (it should be authenticated by system
authentication) while others will be authenticated by radius server. Please
note here , I am not talking about access-reject all time for root , I am
talking for request shouldn't go to radius server if login user is root.
Please provide me help in this if any body have any idea.
Is is feasible or not?.