It was announced on June 13 that Chelsea and Bayer Leverkusen had reached an agreement for his transfer and the 22-year-old's move to Stamford Bridge was confirmed after paperwork was completed.
He said on chelseafc.com: "I am so happy now I have signed and it is an honour for me to play for this club, with this team and for these great fans. I am really looking forward to it."
Source: PA
Source: PA