Mainz has turned down an offer from English Premier League club Leicester City for Japan international striker Shinji Okazaki, according to a report on Friday in the online edition of Allgemeine Zeitung.
"People always say we could get €12 or €13 million if we sell Okazaki but there is no guarantee we could sign someone that has the same scoring power," Mainz manager Christian Heidel was quoted as saying.
Okazaki, 28, has scored eight times in 16 league appearances this season.
Heidel was quoted as saying he might have reached a different decision if Mainz was not just one point above the relegation zone with 18 points from 17 games.
"If we had 25 or 26 points right now then maybe I would have made a different decision," he said.
According to the report, penalties aside, Okazaki is among the top three Bundesliga scorers over the last 18 months since joining Mainz from Stuttgart.
Leicester had reportedly offered £8 million for Okazaki, who scored 15 times last season, becoming Japan's most prolific scorer in a single season in a top European league.
Mainz's decision not to sell Okazaki could come as a blow to the former Shimizu S-Pulse striker, who earlier this week told Kyodo News that a move to England's top flight would be a dream come true.
"It has been a dream of mine since my youth to play in the Premier League and I have been watching the Premier League since I turned pro," he said at Japan's training camp in Australia at the Asian Cup.
"Japanese players have not been able to do well in the Premier League but I would like to experience it for myself. Even if I was to risk leaving Mainz it would still be worth it."