The 33-year-old, who has helped the Gunners secure Champions League football again next season, was allowed to depart due to the brilliance of Belgian goalkeeper Thibaut Courtois.
But, with Courtois struggling for form under both Jose Mourinho and Guus Hiddink, it has highlighted just how wrong Roman Abramovich was to sell him to their fierce rivals.
SIGN UP NOW
Want to become a GMS writer? Sign up now and submit a 250-word test article: http://gms.to/haveyoursay4
Despite helping Chelsea win trophies galore for 11 years, Cech was unceremoniously dropped from the side in favour of Courtois, who had returned from three successful years on loan at Diego Simeone’s Atletico Madrid.
And though the Blues waltzed to the Premier League title in 2014/2015, Cech played a peripheral role, featuring just 16 times across all competitions, his lowest tally since his first season at former club Blsany in 1999.
As the dust settled on Chelsea’s party celebrations, it became clear that Cech was on his way out and, with Manchester United eyeing possible replacements for David de Gea, many expected him to move to Old Trafford.
Instead, his desire to remain in the capital swung the pendulum Arsenal’s way, with Arsene Wenger finally signing a world-class goalkeeper after years of dodgy performances of Manuel Almunia, Wojciech Szczesny and Lukasz Fabianski.
Despite making a mistake on his debut in a 2-0 defeat to West Ham, Cech has since recovered and delivered a string of impressive performances that helped them finish 2nd.
The Czech Republic international has been in fantastic form and his 15 clean sheets have been a silver lining in an otherwise difficult campaign for the north London club, albeit one that ended on a positive note.
Cech’s experience has been key, even if he has been unable to lead the club to the league title that their supporters crave.
A year ago, Courtois was regarded as one of the best goalkeepers in the top flight, but the Belgian has had some shambolic moments this season and a new start at Real Madrid in the summer could be in the offing.
That would leave the Blues with just Asmir Begovic to rely on and new manager Antonio Conte may be reluctant to rely on the former Stoke stopper.
Conte will no doubt be wishing that Chelsea had kept Cech and, with the Blues set to have no European football next season, landing a quality goalkeeper could be a problem.
Should Chelsea have kept Petr Cech? Have your say in the comments.