#4 Is Cesar Azpilicueta past his best?

Since the start of the season, Chelsea's defense, and more so Cesar Azpilicueta, has been under the pump a little bit. The right back was a fault for two of the goals conceded against Manchester United, the one against Leicester City, and another against Norwich City.
At the moment, he seems to be extremely industrious while going forward because of the way Chelsea setup, but the Spaniard has seen himself beaten time and time again, both in one-versus-one situations and in the positional sense.
The spotless nature seen from his side over the last five years or so seems to be missing at the moment, as Azpilicueta has endured significant lapses in concentration so far this season.
The home team started the second 45 minutes in the most casual fashion; allowing Sheffield to press them quicker. The Blades earned a throw, and Azpilicueta was undone way too easily by Stevens.
It was however, a well-taken goal by Callum Robinson, who opened his body up and seamlessly put the ball beyond Kepa, who's yet to keep a clean sheet this season.
Zouma again, had to do a lot better in perceiving what did eventually come his way in the form of a cross. The Frenchman was nowhere near the Sheffield forward.