Torino full-back Davide Zappacosta has only just started his medical with Chelsea, so the €25m transfer will go down to the wire.
The deal for the Italy international was completed this morning and he only flew out to London this afternoon.
According to Sky Sport Italia, Zappacosta only began his medical with Chelsea doctors at around 21.00 UK time, with two hours to spare until the transfer deadline.
There is still time, as the Premier League window shuts an hour later than the Italian one.
Torino have already signed his replacement, Cristian Ansaldi, on a two-year loan with obligation to buy from Inter for a total €4m.