Kai Havertz said he chose to join Chelsea this summer because winning titles with them "was worth more" than any other club.
The midfielder has joined Bundesliga club Bayer Leverkusen for a fee of up to £ 71million.
Havertz has been linked with Barcelona, Real Madrid and Bayern Munich, but said Chelsea's vision drew him to the club.
“For me it was important to have a club with a vision,” he told Sport Bild. “The club is moving. We are a young team with a lot of great players. We think aggressively.
“We want to build something here and attack. It motivates me. And then, a title with Chelsea is worth just more.
“A transfer like this doesn't happen overnight. I had enough to go through all the options and things that were important to me. I watched a lot of the Premier League on TV anyway and knew Chelsea very well. "
Havertz scored four goals in 10 appearances for Chelsea but missed out on the Premier League win over Sheffield United after testing positive for COVID-19.
His German international team-mate Timo Werner also moved to Stamford Bridge and Havertz said they helped each other settle in England.
“I help Timo with good passes on the pitch and at the start he helped me with a lift to the training ground,” he added.
“Of course, we do a lot of things together. It helps a lot. But we also have to go our own way to fully settle here.
“For me, moving to England is also an important step for my personal development. "