The signing was announced on July 1st, the opening day of the transfer window and is likely to be the start of a handful of signings for the reigning Premier League champions.
The 35-year old impressed for Manchester City last season, filling in 26 times throughout the campaign and performing admirably when called upon. Despite beginning the season as a backup, Caballero seemed to make the position his own toward the end of the season and helped Manchester City qualify for the Champions League by finishing third.
The Argentine also made notable penalty saves in the Champions League, proving to be the perfect goalkeeper to rotate in and out of the squad.
Caballero made 47 appearances over his three seasons with the Manchester side, the most notable being his performance in the 2016 League Cup Final. The 35-year old left Manchester on the expiry of his contract and joined Chelsea as the replacement for Asmir Begovic.
While Caballero will be a backup at his new club, his experience and talent will be crucial to Chelsea as they return to fighting on all four fronts this season. With Antonio Conte's side expected to play over 50 games next season, Caballero should see plenty of action in cup competitions and filling in during the league if necessary.
Chelsea were in the market for a backup goalkeeper after selling Asmir Begovic to Bournemouth for £10 million earlier in the summer. Caballero's availability and reported desire to stay in England made it a perfect fit for both parties.