Bayern Munich have had a reported offer of €10 million for Bayer Leverkusen midfielder midfielder Arturo Vidal rejected, according to Leverkusen’s director of football Rudi Voeller.

“Our principle is that Arturo is too important to us and we want to keep him in any case, whether the offers come from Munich or Napoli, they are not high enough to force us into a rethink,” Voeller told German magazine Kicker.

Voeller said there have been conversations with various interested parties for the 24-year-old Chile midfielder, but “that changed nothing in our attitude” with Vidal likely to be offered a contract extension soon.

With 28 caps for Chile, Vidal is under contract until 2012 and is a favourite of former Leverkusen coach Jupp Heynckes, who will take over as Bayern boss when pre-season begins on July 1. Bayern are reported to be still trying to sign Manchester City defender Jerome Boateng with an offer of around €20 million said to have been tabled.

Meanwhile, Bayern’s CEO Karl-Heinz Rummenigge has said he is confident the Bavarian giants will sign Japan’s attacking midfielder Takashi Usami from Gamba Osaka.

The 19-year-old enjoyed an impressive breakout season in 2010 and won the J-League’s Best Young Player award.

“It looks good,” Rummenigge told Kicker and Gamba’s sporting director has confirmed the player has a release clause in his contract to join an overseas club.

On Wednesday, Bayern completed the signing of goalkeeper Manuel Neuer, who signed a five-year deal, while striker Nils Petersen has joined from Energie Cottbus and Brazil defender Rafinha from Genoa.