If Paulie beats Hatton, the Ricky will have clear evidence that his career is getting close to a close. Ricky's style is a style that may be exciting, but typically leads to a short career. Paulie has slowed in his recent fights as well, and has been very lucky to get the nod (especially against Ngoudjo).
The only thing PM has is a fast jab and it's not strong enough to phase Hatton. So..........a loss to Malignaggi IMO would be devastating to Hatton's career maybe not end it, but certainly would hurt it.