Shutdown CBs?

[X12Celtics3]

In my previous franchises with the Patriots, McCourty was spectacular. However, for whatever reason, in the new, post-Superbowl update franchise that I started (in which McCourty has a higher rating than in my previous franchise) he seems to be getting destroyed by everybody, both in man and zone. He is racking up tackles, but thats only because every ball thrown his way is a completion, it seems. I've tried zones, man coverage, and doubling his receiver, but the only thing that seems to work is blitzing and hoping that the pressure forces a poor throw.

Kind of odd... in my last franchise, he was tied for first in the league with interceptions his rookie year and the defense was rolling. In this new one, the defense is struggling immensely and I have by far the worst turnover ratio I've ever had. I don't throw many picks, but BJGE (who never fumbles in real life) and Edelman have three or four fumbles each, and my defense just can't seem to force fumbles or catch any easy interceptions this season.

Just thought I'd share my minor frustration.