Off topic, but Im always a bit suspicious of manager speak. I tend really to take it with a pinch of salt rather than give it much gravitas.
Simply because, a manager always has an agenda, something to gain (or lose), and is also bound by certain etiquette when speaking publicly.
It could be he genuinely meant every word.
It could be he knows Sissoko has no confidence, and while he didnt think he was particualrly good he did think bigging him up might help him find some confidence and hopefully form.
It could be he doesnt give a brick about Sissoko, he just wants it to look like he is in the squad and we intend to keep him so come January his price isnt completely bargain basement...
There are so many angles that could be being played its impossible to really believe anything.
And that goes for all managers in pretty much all circumstance! How often do you think Mourinho is speaking honestly and sincerely?!