It's a great move by Conte, this is. He's laying down a marker in the dressing room. Terry has left and Costa behaved like a worm during a crucial part of their season. It could have derailed their season.
Binning Costa off, bringing in Lukaku (who although probably not as good is just as, if not more, productive) and acting like a proper Chelsea 'manager', not so much a head coach, puts him in a really strong position. It's the sort of thing Ferguson would do in his prime. Micro-manage the halfwits (even potential halfwits) and feck them off when the opportunity arises. Good on him.