The La Liga giants made an offer before the transfer window deadline but Bayer declined to enter talks.
Bayer CEO Michael Schade was quoted as saying: “Çalhanoğlu is not for sale.”
Çalhanoğlu’s representative Bektaş Demirtaş also revealed that his client is happy at Bayer and still has four-years left on his contract.
Demirtaş said: “We did not enter negotiations Hakan has an agreement with Bayer and is very happy at the club.”
Speaking live on the Derin Futbol show Turkish football pundit Ertem Şener claimed that United are expected to make a €36 million offer before the transfer deadline.
Serie A giants Juventus have also set their sights on the free-kick maestro according to Radyospor.
The 21-year-old has already scored twice this season including a free-kick against Hannover 96 – his 22nd free-kick goal.
Çalhanoğlu joined Bayer from HSV on a €15 million transfer last season and was selected as the sixth most valuable U-21 players in the world list by Soccerex.