Suppose I wish to find the homotopy classes of maps of $B^3 \rightarrow M$ which along the boundary are fixed by a (particular) map $f: S^2 \rightarrow M$.

What can I say about the homotopy classes of such maps? 

I am sorry if this is a trivial question; at first I thought it may be $\pi_3 (M)$, but I am not so sure...

Thanks!