Jose Mourinho's return to Stamford Bridge for a second spell in the managerial hot-seat remains a work in progress, with the Blues still in need of some fine-tuning.
Setbacks at home and abroad against Everton and FC Basel highlighted that fact, with Chelsea yet to fire on all cylinders.
Mourinho has also admitted that he is yet to settle on a favoured starting XI, with some of his selection choices raising a few eyebrows.
Chelsea have, however, collected back-to-back victories in their last two fixtures - seeing off derby rivals Fulham in the Premier League and Swindon Town in the Capital One Cup - and Cahill claims positivity has returned to the ranks.
"It was a tough week, especially when we lost back to back," the England international told Chelsea TV.
"But we've responded really well. Two wins, two clean sheets. Happy days at the minute."
Cahill admits that a change in approach has taken the Chelsea squad a while to get used to, with Mourinho demanding more of a collective effort from his side.
He added: "He really expects you to defend and know where to be. Not just the back four, but everybody when we lose the ball.
"I don't mind playing higher. It's difficult to play high against people with real, real pace. (But) I'm quite comfortable with playing high and I think the lads are."