Bundesliga club respond to rumours that Chelsea want to sign their star player

Stuttgart defender Antonio Rudiger started for Germany this weekend, and Chelsea are believed to be monitoring his progress.

Chelsea have made a strong start to the season under Jose Mourinho, with his summer spending paying dividends so far. Mourinho forked out over £100m this summer in order to bring the likes of Filipe Luis, Cesc Fabregas, Diego Costa, Didier Drogba and Loic Remy to Stamford Bridge, and with six wins and one draw from the opening seven games of the season, the Blues are red-hot title favourites.

January spending is likely to be at a minimum for Mourinho, though adding depth at centre back and in centre midfield could be a priority. With the transfer window already getting closer, speculation has begun in earnest, and Stuttgart defender Antonio Rudiger is believed to be a target for Chelsea.

Rudiger, 21, was initially on the books at Borussia Dortmund before joining Stuttgart in 2011, and having made his debut in January 2012, the youngster has virtually been a fixture of the side ever since. With 35 appearances last season, Rudiger is Stuttgart's prized asset, and having made his way into the Germany first team, a number of clubs are believed to be interested.

Manchester United and West Ham are also reportedly monitoring Rudiger, who can play at both right back and centre back, but speculation over the weekend suggested that Mourinho's Chelsea were hoping to strike a January deal - and tie down two of the game's top young centre backs in Kurt Zouma and Rudiger.

However, according to Bild, Stuttgart have rubbished the notion that Chelsea have already been in negotiations over Rudiger, and they say that given the good relationship between the clubs following the loan deal involving Oriol Romeu's move to Germany, they would have heard from Chelsea by now.

"Our intention is to extend the contract of Antonio Rudiger," said Sports director Jochen Schneider. "We have, with other things as well as borrowing Oriol Romeu, a good relationship with Chelsea, they would make themselves known to us."

Register for CHELSEA team updates

Register for HITC Sport - Daily Dispatch