Maybe that tells you that Conte lets Vidal rest during easy games?
I can't believe people still think Marchisio is on his level.
Games missed this season
Marchisio: Fiorentina (away, draw), Catania (away, win), Bologna (home, win), Shakhtar (home, win), Cagliari (home, win), AC Milan (home, win), Parma (away, draw), Udinese (home, win), Lazio (away, loss), Chievo (away, win), Roma (away, loss), Celtic (home, win)
Vidal: Genoa (away, win), Chievo (home, win), Bologna (home, win), Torino (home, win), Sampdoria (home, draw), Siena (home, win), Catania (home, win)
So without Vidal in the starting line-up our record is 6-1-0, without Marchisio it's 8-2-2. Conte from time to time tends to start semi-hard games without Marchisio and almost always when that happens we fail to win, while we're pretty comfortable without either of them against small teams. Conclusions? I'd say Marchisio is very important and whenever he is missing (or plays awful like against Bayern), it hurts the team badly.