Petr Cech has re-signed with Chelsea as part of their backroom team.
The former Czech international retired from football at the end of last season with London rivals, having joined from the Blues in 2015. He made his final appearance with the Gunners in last month's Europa League final in Azerbaijan against his former club. Cech ended up conceding four goals as they lost on a 4-1 scoreline in Baku.
He has rejoined the Stamford Bridge club as its new Technical and Performance Advisor.
His job will be to provide a link between the first team and academy and to work closely with the coaching staff.
He made over 440 Premier League appearances with the two London clubs, over a 15-year career in England.
During his spell between the posts at Chelsea, he won 13 major honours, including four Premier League titles as well as a Champions League medal in 2012 - as Di Matteo's men beat Bayern Munich.
In his career playing at Stamford Bridge, he became the club's clean-sheet record holder and the made the most appearances for a player from outside England.
He missed four months of football in the 2006-07 season after sustaining a head injury when he collided with ex-Ireland international Stephen Hunt while playing Reading at the Madejski Stadium. Hunt's right knee hit Cech's head, leaving him to require treatment.
He made his comeback against Liverpool in the Premier League in January 2007 - wearing a rugby-style head guard, which he played with for the rest of his career.
On his return to Chelsea, the 37-year-old said he is "very privileged to have this opportunity to return to Chelsea again and help create the best possible high-level performance environment to continue the success of the club."
Meanwhile, the Blues' Director, Marina Granovskaia said they always wanted to bring Petr Cech back to the club when he retired from playing, calling him "one of the most dedicated, successful and thoughtful professionals we have ever had."
Written by Ben Finnegan