The former England international goalkeeper has signed a one year deal to join up with the Blues at Stamford Bridge and is expected to provide backup to Thibault Courtois and Willy Caballero.
Both Eduardo and Jamal Blackman have left the club this summer for temporary deals elsewhere, meaning the Blues needed to add someone to their side, with Green an inexpensive but experienced addition.
The 38-year-old, who had been considering retirement this summer, will also help Chelsea to reach their quota of eight home-grown players in the squad, something the club were keen to rectify ahead of the upcoming Premier League campaign.
Green himself admitted he had been pretty shocked about the 24 hours that occurred prior to the deal and revealed that it was just a short conversation.
“It has been a whirlwind 24 hours,” he told the club’s official website.
“You are thinking about your career and where you want to go and then you get a phone call like this, and it is a short conversation.
“It has been a pretty dramatic time for me and I can’t wait to get started. I am absolutely delighted and it is a thrill and an honour to be here.”
A former West Ham United star, Green has experienced the game at all levels and, although he is not expected to feature much for the first-team, he will be on hand to help guide and develop some of the club’s youngsters into becoming better professionals.
The shot-stopper becomes Chelsea’s second summer signing in this transfer window as he follows Jorginho’s arrival from Napoli, although Maurizio Sarri will want to bring a few more bodies in before the August 9 deadline.
Quotes via Chelsea FC.