Everton have reportedly agreed a deal for Hajduk Split winger Nikola Vlasic.
According to a variety of sources, the deal to take Vlasic to Goodison Park is reported to be worth €10m (£9.2m).
The Croatian Under 21 international has already sampled the atmosphere at Goodison Park, where he impressed against the Blues in their recent Europa League playoff games, with Everton running out 3-1 winners on aggregate to qualify for the group stages.
Everton have already spent £150m in this transfer window breaking their transfer record twice, but are set to have a busy final 48 hours with several players arriving and departing the Merseyside club.
Chelsea striker Diego Costa has been heavily linked with a short term loan move, while it is known that Koeman still wants another centre back. Meanwhile, Oumar Niasse has been linked with a £10m move to Crystal Palace or Brighton, while Kevin Mirallas could also depart.