Brazil winger Willian has confirmed he has left Chelsea after seven years at the club.
Willian, 32, missed Chelsea's Champions League defeat by Bayern Munich on Saturday with an ankle injury and is now out of contract.
BBC Sport reported last week that Arsenal were closing in on a deal for the midfielder.
"The time has now come to move on," Willian wrote in an open letter to Chelsea fans.
"I leave with my head held high, safe in the knowledge that I won things here and always did my best in a Chelsea shirt."
He made 339 appearances for the club after signing from Russian side Anzhi Makhachkala for £30m in 2013, becoming one of the most popular players at Stamford Bridge in the process.
He has won five major honours with the Blues, including two Premier League titles and the Europa League, and won the club's players' player of the year award twice.
"There were so many happy times, some sad, there were trophies and it was always very intense," he added.