Spurs have picked up just one point from a possible 12 in their last four games, with a last-gasp Rafael van der Vaart header sparing the North Londoners' blushes during Wednesday's 1-1 draw with Stoke City.
Harry Redknapp's side have not won at the home of their London rivals since 1990, and January arrival Cahill is hoping to extend that record, despite losing 2-1 to Manchester City last time out.
Spurs currently sit five points ahead of the Blues in fourth place, and the former Bolton Wanderers defender is confident they can cut that to two with a win at the weekend.
"Arsenal are having decent form and Spurs have been hit the last few games," said Cahill.
"It is hard to keep that momentum going throughout the season. Spurs have been absolutely fantastic but it is tough to keep it going every single game, week in, week out.
"You’ll always have a blip in the season and maybe theirs has come now.
"We’re at home, where we have some confidence now and we are looking to get the positive result we need.
"We have built some momentum of late and the camp is positive at the minute."
Cahill opened the scored for Chelsea at the Etihad Stadium, but goals in the final 12 minutes from Sergio Aguero and Samir Nasri saw the Blues suffer their first defeat in five games.
"We were unlucky against City but we can't let it affect us because we have huge games coming up."
