The phenyl group, I presume, is a radical. i.e, one carbon has no hydrogen attached to it, just an odd electron.
The hybridization of that Carbon atom is sp2. 2 sp2 orbitals form C-C sigma bond, and one p-orbital is used for C-C pi bond. Now the odd electron lies in the 3rd sp2 hybridized orbital, which would have overlapped with the s-orbital of Hydrogen if the molecule were benzene.
So, we have just one valence electron.
Hope this helps