I remember him playing a pretty good last season until his injury. Very consistent, good positioning and generally few flaws in his defensive works. And while hes not the agile/dribbling type of Full Back, his style is actually right for the duties he has on the left flank, where he can go offensive with his good speed (as there is usually more space on the left, esp. after a long ball from the other flank) and he is very adapt to the passing and buildup play.
He just started to become a bit error-prone after he got back from his injury and maybe also losing some confidence after his back-to-back sent offs in the CL and La Liga. He is still not in last years shape, but to call him "worst players ive ever seen" is a bit of a joke.