Sturridge's biggest issue is he's our #1 ... Last year, he had Suarez taking a lot pressure off of him (and visa versa). Teams didn't focus as much on either, and if they did, bang punished. We also had tremendous movement behind them with Coutinho and Sterling buzzing.
This year, studge gets all the attention of the defense and without another goalscoring option, there is less damage done by Coutinho and Sterling ...
Studge is still a really good player but I'm not sold he can be THE striker without another proper striker around him.