Hoffenheim general manager Alexander Rosen insists that the club will not sell midfielder Sejad Salihovic.
A fine brace by Vedad Ibisevic helped Stuttgart secure three points at Hoffenheim to lift them into contention for a Europa League spot for next season.
Hertha Berlin are being linked with former players Sejad Salihovic of Hoffenheim and Fortuna Dusseldorf's Assani Lukimya-Mulongoti.
Bosnian Sejad Salihovic has called for more from his Hoffenheim team-mates if they want to avoid a Bundesliga relegation battle.
Bundesliga leaders Hoffenheim have secured the services of Sejad Salihovic for a further three years.