The Brazilian departed Stamford Bridge in the summer to move across London after seven years with the Blues.
He won two Premier League titles, the FA Cup and the League Cup with Chelsea, but believes that he will soon be celebrating another league title under Mikel Arteta’s guidance at the Emirates.
“I had great years at Chelsea,” he told the Daily Mail.
“But now it's a different colour, a red colour, and it felt good from the start.
“Arsenal have a great coach and a great chance to fight for titles. We can win the league. Maybe not this time but next time. I'm motivated to have more success.”
Willian also explained that he asked for a three-year deal during contract negotiations with Chelsea but was only offered two more years.
“It was difficult,” he said.
“They knew how much I wanted to stay. I wanted to be a legend for the club. It was strange.
“But Arsenal was different. Every day they called my agent and wanted to meet or talk. They really wanted me to go there.
“That's the difference. I see one club that made a lot of effort for me to go there, pushing a lot. And another who just said: 'Two years or go'.
“I was a little bit sad with that but I respected Chelsea's policy. Now it's a new club, a new challenge, a new experience, a new life. Now it's time to work to try to win more titles.”
The Brazil international also revealed that Barcelona came calling for his signature after the 2018 World Cup, but any chance of a move was blocked by his employers.
“It was £50 million, I think,” he recalled.
“A big offer. Four years. But Chelsea said no. I think if I forced it then it would have been a fight and I didn't want that. So I was happy to stay.”
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