  We study the spherical collapse model (SCM) in the framework of spatially
flat power law $f(T) \propto (-T)^{b}$ gravity model. We find that the linear
and non-linear growth of spherical overdensities of this particular $f(T)$
model are affected by the power-law parameter $b$. Finally, we compute the
predicted number counts of virialized haloes in order to distinguish the
current $f(T)$ model from the expectations of the concordance $\Lambda$
cosmology. Specifically, the present analysis suggests that the $f(T)$ gravity
model with positive (negative) $b$ predicts more (less) virialized objects with
respect to those of $\Lambda$CDM.
