The 22-year-old, who has been capped 11 times by Japan,??scored 13 goals in 33 matches in his first J-League season to equal a newcomers’ record and had been a transfer target for the Blues, who were reported to have made a ??4m offer for the player.
But Muto has turned down the chance to sign for the Premier League champions in favour of joining Mainz, where he will play alongside his international team-mate Shinji Okazaki.
“I wanted to keep my expectation realistic and play for a team that fits my level,” he said.
Muto said he had been impressed by Mainz’s desire to sign him and that he wanted to continue his goalscoring form when he makes the switch to the Bundesliga following the completion of the first stage of the Japanese top flight in June.
“I began to want to compete at a level above. They really showed they wanted me,” said Muto. “From the word go I’d like to focus on scoring goals.”
Chelsea earlier this month announced their ???largest ever commercial deal??? with Japanese tyre manufacturers Yokohama Rubber Company and Jose Mourinho said cryptically of the proposed Muto transfer: “That???s modern football. That???s modern management. You cannot close completely the door to commercial interests.”