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.
Chelsea will once again be without Fernando Torres (knee), so either Samuel Eto'o or former Newcastle striker Demba Ba will lead the line.
