Leicester have agreed a fee to sign Freiburg defender Caglar Soyuncu.
Sky Sports News understands the deal could rise to around £19m.
Soyuncu joined Freiburg from Altinordu in 2016 where he went onto make 50 appearances, scoring once, for the Bundesliga side.
The 22-year-old has made 15 appearances for Turkey after being called up in November 2015 from then head coach Fatih Terim.
It is understood he is expected to travel to Leicester to have his medical on Deadline Day.
Filip Benkovic could also join Leicester but despite the possibility of bringing in two defenders the club have stated Harry Maguire is "categorically not for sale in this transfer window".
Manchester United are interested in signing the England international and have already had two bids turned down.
Leicester face United in their opening match of the Premier League season on Friday, live on Sky Sports.