Hate to say it but it's this guy.

Once Rondo came back from injury the C's started resembling the team pre-Rondo injury. Standing around and not putting maximum effort on the floor. If you watched this team long enough you'll notice they tend to get bored and need a spark to getting going. The C's were getting energy off the bench from Bradley, Moore, and Sasha.
Rondo can bring that energy to get the team going but he doesn't do it enough. He plays so passive and it bogs down the whole team. If this is truly his team like everyone says it is, why doesn't he show up night in and night out?
Look at the upcoming schedule. Things really don't look good right now. C's could fall well under .500 once again.
vs Chicago
@ Chicago
@ Detroit
@ Dallas
@ Oklahoma City
@ Cleveland