The rumour does not involve Fernandinho'd partner, it is another of the players. Out of respect and the absolute nonsense nature of the rumour, there's no need to say who.
The reason for his form is, like with Zab, Mangala, and the defensive side of the team in general, the shite defensive tactics of Pellegrini (there basically aren't any), and the high line he persists with. Add in the World Cup and the accompanying mental exhaustion, and it's no great surprise.
I'm looking forward to seeing him next season under Klopp, rejuvenated and in a team balanced between attack and defence.