Spurs host Southampton on Sunday while City take on top-four rivals Liverpool at the Etihad Stadium, and Cahill believes that both sides must win if they are to keep themselves hanging on in the title race.
"The manager told us to keep playing our football and wins are all that matter at this stage," he told reporters.
"We only had two Premier League games in this month. We managed to get the results and now we can sit back and watch tomorrow's games. There will be pressure.
"I have played in that situation where a team has won and you have to go out and get a result."
No team has ever failed to win the Premier League title having built a 13-point lead.