Michail Antonio was already a rumored Chelsea transfer target last summer, so his re-appearance in the current window is perhaps not at all surprising, especially given West Ham's generally poor time of things so far this season. It should be however noted that Sky Sports have already refuted much of this story by claiming that West Ham United have no intention of selling the 26-year-old.
Then again, the original rumor, as per ESPN, only claimed that Chelsea were monitoring the England international's situation at the Hammers. Plus, it's not like West Ham are going to just acquiesce and offer up the versatile Antonio at first asking — in fact, they're expected to offer him a new and improved deal on the five-year contract he signed in 2015. So Chelsea will have to be persistent if we think he fits Conte's profile of a "right player".
Is Antonio a "right player" for Chelsea? Possibly. He's known to be quite versatile, which surely is a plus for Conte. West Ham boss Slaven Bilic has been using him as a forward for some time, but he's played just about anywhere in midfield and attack and even full back ... though apparently he doesn't like that as much.
Antonio is West Ham's leading goalscorer at the moment, which will no doubt make them extra reluctant to let him go. Add in the homegrown tax, and his fee might start approaching unreasonable values. None of the sources even venture to take a guess at what that might be.
If you have to ask, you can't afford it, as the saying goes...