Willian has admitted he was unhappy at Arsenal, and he already wanted out after just a few months with the club.

Willian joined Arsenal on a free transfer in the summer of 2020, and he initially looked like making Chelsea regret losing him after an impressive debut performance.
It didn’t last, and by the end of the season Willian’s time in North London was already over. Speaking about what went wrong, Willian concedes he just wasn’t happy at Arsenal.
“I was not happy, that’s why I didn’t perform. I don’t want to go into the details, but I wasn’t happy,” Willian said.
“So, when I arrived there I was happy, from the beginning I was motivated, I wanted to do well, new club, new mates, new projects.
“After three months, I told my agent ‘please, I want to go’.
“I don’t want to speak bad about the club because it is a big club, has a big history in football, big players played there before it’s a big club.
“But it didn’t work, it was of course the most difficult time of my career.”

In all honesty, this just confirms what most of us could see on the pitch. Willian went through a bad period of form and just gave up, barely even trying for the rest of the campaign.
There were moments where you could see him finding some motivation, such as in the early Europa League knockout rounds where he had a couple of positive contributions. But for the most part, he just didn’t seem to care.
The positive thing is that he at least made sure things ended in the right way, giving up a lot of money to cancel his contract.
As much as it would have been better if he’d rediscovered his form and contributed positively to Arsenal’s performances, the next best thing was definitely accepting it wasn’t working and moving on without demanding a major payoff.