Petr Cech sought approval from Chelsea owner Roman Abramovich before sealing a move to continue his Premier League career with Arsenal.
Cech ended 11 trophy-laden years at Stamford Bridge by completing a move to Emirates Stadium for an undisclosed fee on Monday.
The 33-year-old was first-choice for Chelsea until last season, when Belgium international Thibaut Courtois helped Jose Mourinho's team to regain the league title in an impressive breakthrough campaign.
In an open letter to Chelsea fans, Cech revealed that time spent on the sidelines made him appreciate how much he desired regular first-team football and he was grateful to Abramovich - who financed his signing in July 2004 - for helping the move to Arsenal go through.
"The limited playing time gave me the chance to refresh and rest mentally as well as make me realise just how much I enjoy playing football at the highest level, because I missed it badly and every game day I was not involved,” Cech said.
"That's why I spoke to Mr Abramovich about me staying in the Premier League and I'd like to thank him from the bottom of my heart for his support in this matter. It means so much to me because without him, Chelsea Football Club would not be where it is now. He deserves huge credit for what he has done for the club and for all of us."
Cech won every major honour in English football at Chelsea, along with collecting the UEFA Champions League and UEFA Europa League in 2012 and 2013 respectively, and he envisaged closing his career with the club.
"I thought this would never happen but it is time for me to say goodbye to Chelsea Football Club," he said. "The club I have lived every single minute for since joining in July 2004, the club in which I thought I'd hang my gloves and boots one day and finish my career. But life doesn't always turn out the way you think it will.
"Since 2004 it has been an incredible journey with so many highs and not many lows. We have managed to win every single English trophy as well as the Europa League and the biggest of all - Champions League. Looking back at all the achievements, including our first ever [Premier League and FA Cup] double in 2010, back-to-back titles in 2005 and 2006, and multiple EPL and FA Cup wins, I couldn't be more proud!! As a team we made history together!!”
Paying tribute to Chelsea's fans, Cech added: "I did everything for you and you gave me your love back. I'll never forget it. It will stay with me forever. We will meet again but this time I will be in the other goal - I hope you will remember our history and understand it is time for me to begin a new adventure.
"I wish everybody at Chelsea Football Club all the best for the new season and for the future. Thank you for an incredible 11 years."
