* Gives Sissoko the much needed confidence that he's an important part of the squad, which could hopefully translate into better performances thus justifying his inclusion. As the Euro 2016 tournament showed, he can actually look like a decent player when he's properly motivated.
* If you are trying to sell a player & trying to the get the most for him you don't tell potential buyers that he's crap. The value would just plummet & you would end up flogging him for peanuts. Hopefully, with the vote of confidence he's received from the manager translating into better performances, potential suitors may think, "maybe Sissoko could be one our most important players."
Wishful thinking, but I have to believe that this is the strategy here; it's all I have to hold onto.