The Blues are just four points behind Manchester City going into Sunday's intriguing clash at the Etihad Stadium.
"We've obviously got a huge game tomorrow night, and then a massive game on Sunday," said Cahill.
"If we get a positive result on Sunday then that opens it right back up. We're taking it one game at a time but we'll be looking to do that.
"It'll be tough game away from home, but if we do get a positive result then obviously second place is within touching distance."