Hex key nut missing from rotor. Is this a problem?? PICTURE INCLUDED

[chicken_loops]

http://i5.photobucket.com/albums/y190/neogen69/photo2.jpg

Thanks for your help

[osolokes213]

a rubber grommet goes there...not a big problem...might get debris in there tho...

[chicken_loops]

Oh alright. Thanks for your help