The 21-year-old has enjoyed a solid season for the German club, making 30 appearances, and has already earned nine caps for Turkey despite his young age.
Mustafa Dogru, the player's agent, has admitted that his client, who is also believed to be on the radar of Manchester City and Manchester United, has his heart set on a move to the English top flight.
"The main objective of the player is to play in the Premier League, that I can tell you at the moment," Dogru told football.london.
"We are negotiating with some clubs, but I can't give the name of the clubs - I'm sorry. Next week we will have some meetings and I think in 10 or 15 days his situation will be clear. [Freiburg] are open to negotiations.
"He is ready [for the Premier League]. He came from the second division in Turkey to Bundesliga 1 and has had a good experience the last two years. The difference between Bundesliga 1 and the Premier League is not as big as from the Turkish second division and Bundesliga 1, so he is ready. He is perfect for the Premier League."
Freiburg are believed to be looking to bring in around £35m for Soyuncu.