Oliver Kahn has advised his former club Bayern Munich to sign Juventus and Italy goalkeeper Gianluigi Buffon to take them onto the next level and make them more competitive in Europe.
Hans-Jorg Butt is currently keeping for Bayern, although he was originally only signed as cover for Michael Rensing, who failed to make the grade after Kahn's retirement in 2008.
However, Kahn feels Butt does not have many years left at the top and a player like Buffon would be the ideal man to help bring the glory days back to the club.
''Bayern have the highest of aims and when you want to reach them, you need one of the best goalkeepers in the world,'' he said. ''I don't want to criticise Butt because he is playing excellently this season, but since Butt is 35, Bayern have obviously got to start thinking about an alternative.''
Having tried and failed with the youth of Rensing, who now seems certain to leave the club in the summer, Kahn insists an experienced player should be the priority.
''The club has got to decide whether to go for a youngster like (Rene) Adler or (Manuel) Neuer, or a proven man; whether to get a foreigner or a German,'' he added in Sport Bild magazine. ''For me, a world class goalkeeper is one who is the number one in his national team and plays in the Champions League at a top club, a club which is always challenging at the top of one of Europe's strongest leagues.
''Whoever has proven that for several years and plays consistently at the highest level is a world class goalkeeper. Juve's Buffon is world class. So is (Iker) Casillas of Real Madrid or Petr Cech of Chelsea.''
When asked who his choice would be, Kahn added: ''Gianluigi Buffon of Juventus''.