3 reasons come to mind:
1.they don't know who their owners will be
2.gasol was injured most of the year
3.players didn't like playing for fratello
Reasons 2 and 3 have recently been corrected.
Reason 1 is still up in the air.
The team seems to be playing a lot better now that Frat is gone.
They are definitely scoring more points and more exciting to watch.