The 29-year-old defender has 18 months left on his five-year-deal, but according to The Times, Chelsea are willing to give him only a one-year-extension.
Cahill has been talking to the club about a new contract since last season, but with no effect, and now there is a genuine fear, the club might not offer him a long term contract at the club.
The centre-back currently earns £100,000 a week, as per The Sun, and he is keen to commit the rest of his career at the Bridge but time is running out.