The Turkish international scored in his most recent game for the Crescent-Stars in the 2-0 win over Czech Republic in Euro 2016 Group A.
Barcelona could face competition from Manchester United who have been closely linked with the 21-year-old playmaker.
United will have to part ways with £30 million to prize Çalhanoğlu away from Bayer according to Tutto Mercato Web (via the Mirror‘s Aaron Flanagan).
The highly rated 21-year-old playmaker is one of the most sought after players in the Bundesliga and has a brilliant record in Europe playing a direct role in 12 (6 goals, 6 assists) in his 14 European games.
Çalhanoğlu already has six goals and two assists to his name in all competitions this season and has built a reputation as being a set-piece specialist.
The Turkish international star has a phenomenal free-kick scoring record – 22 in the Bundesliga alone.