Fedor has spent far too long not fighting against the top guys.
It's impossible to stay at the peak of your abilities when you are not forced to push yourself against the elite opponents.
He has not had a fight against a TOP guy since Pride folder, to say he has is straw clutching. He really should have gone to the UFC, but regardless his legacy was made in Pride and he really has nothing to prove.
Age and relative inactivity (at least against top contenders) will take its toll on anyone.
You can write off his loss to Werdum because he knocked him down and was basically caught in a submission from it (Lesnar was caught by Mir while dominating him) but he was man handled by Antonio Silva.
He hasn't looked impressive for a while, was struggling against Arlovski until he found a knockout blow (similar story with Rogers) and these are what the americans call 'cans'.
Fedor can still come back, of course he can but you have to wonder if he has the desire to at his age and having already cemented his legacy many years ago in Pride.
UFC is a challenge worth taking for him, but I just don't see that ever happening now so what else? he is on a 2 loss streak maybe he could fight the winner of this heavyweight tournement (but having lost a 1/4 convincingly does he really deserve the shot CURRENTLY?)
I think he needs to fight Overeem, this is what people wanna see in Strikeforce for both fighters its a pretty defining match up. If Overeem is to ever lay claim to being the best in the world now he would have to beat Fedor and if Fedor wants to prove he is still the best he needs to beat Overeem.
After the heavyweight tournement is done, Overeem/Fedor is the only real fight of interest left (unless for example Silva makes a name for himself as it progresses)