Juventus general manager Beppe Marotta feels the club needs to sign "at least another four great players" if they are to be competitive again.
The Old Lady is without a win in four matches and it now looks unlikely that they will qualify for next year's Champions League.
In order to make the jump in quality, Marotta said: "Juventus need at least another four great players. Above all, people of experience who know how to better manage the most difficult situations."
La Gazzetta dello Sport understands that Marotta is interested in Lyon wing-back Michel Bastos, Milan regista Andrea Pirlo, Barcelona anchorman Javier Mascherano and Roma striker Marco Borriello.