I don't attach any blame to Martina. He is what he is, which is at best a Division 1/Championship level right back.
The blame lies with one manager for buying him when he is so clearly below the standard required, and another manager for continuing to pick him, out of position, when it has been clear to everyone that doing so left the team totally unbalanced. Whilst his own individual defensive performances may have very slightly improved of late, the balance of the team has remained a major problem that has never been addressed. It is no surprise to me at all that the return of a non match fit Leighton Baines has coincided with such a marked improvement in performance and results.