The Blues produced a backs-to-the-wall effort to become European champions last season but have failed to keep a clean sheet in their last seven games as they search for a more exciting blend.
"There are times when you look and things might not be as tight, or you're feeling a bit more exposed than normal,'" Cahill told the Daily Mail.
"We have some defensive midfielders who sit in there, which really helps. But sometimes when you do play so attacking, against an attacking team, you are going to get hurt.
"That's probably where we need to be a bit more disciplined, but without taking anything away from our attacking players because their first thought is to go forward and try to score and hurt teams.
"It's hard to get that balance. With the players we've got, if we were winning 1-0 would people be happy with that? Or are they happy with the way we're playing this season? It's entertaining."
Cahill is certainly happy at Chelsea having won the UEFA Champions League just four months after his January move from Bolton. While he admits it was a gamble, the former Aston Villa trainee believes it was one he had to take.
"At the time I moved I was playing in the Premier League week-in, week-out, so the next step was to go somewhere where you're going to try to win things," added the 26-year-old.
"The risk was that there were great players here - you've got David Luiz, who was captain of Brazil not long ago, and JT (John Terry) who has been captain for England and Chelsea for years and years. So you're not going to walk straight in.
"But you've got to take that risk. It's not very often you get the chance to come to a big club and try to win things."
Curiously, Cahill's prospects at club level may be hindered by the international retirement of Terry - one that simultaneously creates an England opening for the defender.
'It is strange," said Cahill. "It's not like JT has come out of the England frame just as I'm getting in - I've been in for the last couple of years.
"But it's a chance for me because you're missing a fantastic player like JT in the England set-up, an established leader who, when available, will always play.
"I spoke to him about it. He supports me and I think he wishes me well with England.
"England have always been blessed with good centre-backs. It's been difficult to get in, but playing here at Chelsea, and getting opportunities, that's given me a chance.
"It's all up in the air again now, isn't it? But it's an opportunity. The door's open there for someone to come in and bed down a position."