Consider a functor between small categories $i:\mathcal{A}\to \mathcal{B}$ which is faithful, not full, and bijective on objects. Consider a functor $F:\mathcal{A}\to \mathcal{M}$ where $\mathcal{M}$ is a combinatorial simplicial model category such that there is no functor $\overline{F}:\mathcal{B} \to \mathcal{M}$ such that $\overline{F}.i = F$. Let $\mathrm{Ho}(\mathcal{M})$ be the homotopy category of $\mathcal{M}$. The composite functor $F':\mathcal{A}\to \mathcal{M} \to \mathrm{Ho}(\mathcal{M})$ can be extended to a functor $\overline{F'}:\mathcal{B} \to \mathrm{Ho}(\mathcal{M})$, i.e. such that $\overline{F'}.i = F'$.
Are there similar situations in the mathematical literature which we could help me to understand what to do ?