There's reason to believe it has already begun.
Ducker released an article yesterday saying that the reason we never bid last summer was because we were "put off by Sportings high valuation of £75m+/€88m+", which is in direct conflict to their President's comments a few months ago, who said that Spurs were the only team to make a serious offer of £58m/€65m, which he had to reject in the end because of crazy add-ons (€20m in CL+PL wins).
This makes zero sense. So their President wanted ~£20m more from us than Spurs apparently...
Ducker also said Sporting now initially wanted £68.5m/€80m too, which we're trying to bring down to £50m/€58m.
So we're now trying to get them to accept less in the January window than they rejected Spurs in the summer...
If this deal isn't concluded in the next few days, I think it's more likely he's not coming.