Branislav Ivanovic's first-half strike on Monday ended City's 100 per cent home record in the top flight and moved the London club level on points with Manuel Pellegrini's second-placed side.
Jose Mourinho played down Chelsea's chances of winning the title after their win at the Etihad Stadium, but his men are just two points behind leaders Arsenal.
West Ham United frustrated Mourinho's charges by holding on for a goalless draw in the last game at Stamford Bridge and England defender Cahill is aware his team can ill-afford to drop points against Newcastle.
He said: "No disrespect to West Ham, we had loads of possession. We spoke about that after the game and that was a blow to stuff two points up at home.
"We're now on the positive end of a great win away from home, so we can't afford to throw that away at the weekend against a tough team.
"We're home again - we should be buzzing with confidence and ready to go again."
Chelsea also have the incentive of exacting revenge over Alan Pardew's side, who beat them 2-0 at St James' Park in November.
Newcastle have triumphed in three of their last four games against Chelsea, but travel to the capital on the back of a dismal 3-0 derby defeat at home to arch-rivals Sunderland.
It would be a major surprise if Newcastle pulled off another victory at the end of a week in which director of football Joe Kinnear resigned.
The club have won just one of their last seven matches and the departure of influential midfielder Yohan Cabaye to Paris Saint-Germain was a major blow.
Leading scorer Loic Remy will play no part at Stamford Bridge as he serves the second game of a three-match ban following his red card at Norwich City.
Midfielder Cheick Tiote is a doubt after sustaining an injury in training this week, while Pardew will also check on striker Papiss Cisse (back).
Yoan Gouffran (muscular injury) and Gabriel Obertan (knee) could both return, but defender Fabricio Coloccini (knee) is set to miss out again.
Chelsea will once again be without Fernando Torres (knee), so either Samuel Eto'o or former Newcastle striker Demba Ba will lead the line.
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