The permanent transfer of Carney Chukwuemeka has been agreed upon by the two parties.
The 18-year-old has been given permission to travel to London to have a medical checkup.
It is believed that he wants to get more game time in the top flight.
Sky Sports News reported in July that Chukwuemeka had no interest in discussing a new contract with the club he has been with since the age of 12.
Chukwuemeka had seen the opportunities given to other young England exports such as Jadon Sancho and Jude Bellingham, so he was interested in talking to Dortmund about signing him.
Even though he was left out of the team's summer tour of Australia, Steven Gerrard was still part of the plans for the season.
The Blues have signed a number of new players this summer.
The transfer window will close at 11pm on September 1st.
Sky Sports has a dedicated Transfer Centre website where you can keep up-to-date with all the latest news. Sky Sports News gives you the ins, outs and analysis of sports.