Blues captain Terry used his programme notes for Wednesday night's Champions League game with FC Nordsjaelland to brand results during his injury absence as "simply not good enough", demanding more "fight and desire" from his team-mates following a six-match winless run he dubbed the worst of his entire Stamford Bridge career.
This week also saw interim manager Rafael Benitez question whether his side still had the same "hunger" after they finally tasted European glory last season.
His players responded on Wednesday night with the club's biggest ever Champions League victory - 6-1 - although they were powerless to avoid becoming the first holders to crash out of the competition before Christmas.
It was the third trophy Chelsea had surrendered in four months following their losses in the Community Shield and UEFA Super Cup and Cahill acknowledged the public dressing downs were warranted.
"If there's a time where it needs to be done then, sure, it's a positive, as long as it's taken in the right way," the England defender said.
"You have to dig in as a group. That's the only way you can go forward."
Chelsea's squad are known to hold no-holds-barred team meetings in the midst of a crisis.
Cahill declined to reveal whether Terry had repeated the sentiments expressed in his programme notes to the players but added: "We've had meetings before at the club, definitely.
"When we need them, we've had them and they stay within the club.
"It's right that the players are upset. They don't expect to lose games.
"They expect to win the majority of games you go out and play. It's not been happening so it's going to be upsetting players and everyone involved."
It is only just over six weeks since Chelsea were riding high at the top of the Barclays Premier League after their second best ever start to a season and in charge of their Champions League group.
As well as dropping into the Europa League, they now find themselves in real danger of sliding out of the top four in the league ahead of Saturday's trip to Sunderland.
Cahill said: "I don't know what's gone wrong - that's the honest answer. It's the same group of players.
"The players have been asking that question themselves and we don't know really.
"Where do you point the finger? It's obviously stuff you need to work on in the training ground.
"It's the same group of players who started the season beating teams and scoring goals and keeping clean sheets.
"There's no reason why we can't get back to that but we were hoping it would come sooner. We've been waiting for that win."
Chelsea are already 10 points adrift of leaders Manchester United and Cahill added: "We can't afford to slip up many more points in the Premier League. We need to get back to the form we had at the start of the season."
Cahill insisted Wednesday night's Champions League demise had not spoilt the memories of their triumph in Munich just 200 days earlier.
But he was not exactly enthusiastic about the Europa League, which he played in during its UEFA Cup guise, branding it "all right".
His eyes did light up at mention of the Club World Cup, which Chelsea will play in for the first time next week.
However, he admitted the punishing run of fixtures were starting to take their toll.
"I've never been involved in so many games," he said.
"It's crazy, really, the amount of games you're playing in the space of a month. The recovery time and everything else that goes with it is tough, I'm not going to lie.
"But it's going to be a good competition for us.
"Hopefully it gives us a little distraction and we come back flying."