Chelsea goalkeeper Petr Cech has been appointed as a technical advisor and performance consultant.
The 37-year-old has won 13 titles, including the title of the European Championship in 2013, during his 11th Chelsea season, proving he is one of the best guards in the world.
After joining Arsenal in 2015, Cech added another title to his list of achievements through the FA Cup.
Chek retired last month after four years with Arsenal after his former side lost to Chelsea in the Europa League final.
"I am very proud to have the chance to come back to Chelsea and help create the best possible environment for high-level performance to continue the club's success over the past 15 years," said Chek.
"I look forward to the new challenge and hope to be able to use all my knowledge and experience in football to help the team achieve more success in the future."
Chelsea said Chick's new job would include technical advice on football, football, football and sports football, as well as a strong link between the club's first club and academies.