Terry rubbished Arsenal goalkeeper Szczesny's claim that Andre Villas-Boas' sacking as manager proved the Blues' players effectively ran the club.
Former Chelsea boss Scolari also warned Villas-Boas' successor "hell" awaited him because of the influence of the squad on owner Roman Abramovich.
Blues captain Terry hit back ahead of Chelsea's Champions League last-16 second leg against Napoli, saying: "We win and lose together at this club - we're all responsible for the results we have.
"As for the senior players running this football club, that's nonsense. That's just the perception from outside. Roman and the board make the decisions.
"On the football pitch, that can affect what happens upstairs of course. If we don't win matches, the board step in.
"People speculating from various different clubs or previous managers, that's complete nonsense."
With Terry sat next to caretaker manager Roberto Di Matteo during this evening's pre-match press conference, it was no surprise to see almost every question posed to the deposed England captain.
This season has been turbulent in the extreme for Terry both on and off the field.
Chelsea's meltdown under Villas-Boas corresponded with Terry facing trial for racism - a charge he denies - and an injury that looked set to rule the defender out until April.
Asked about the difficulties of remaining focused, he said: "I think I've shown that with my performances, despite what's happening off the field.
"I know what I have to do for Chelsea. As captain, I'm very fortunate and privileged.
"If you had said 10 years ago that Robbie and I would be sitting here with such a big night coming up tomorrow [Wednesday], we'd have probably laughed at you.
"But that's the reality. You won't find two other people who care more about the football club going into this game. We represent Chelsea.
"We give that fiery atmosphere in the dressing room and take it on to the pitch and hope everyone feeds off that."
Terry also hailed Fabio Capello for backing him to the hilt during the England captaincy saga that led to the Italian's shock resignation.
Capello quit as manager last month after the Football Association stripped Terry of the armband ahead of his trial for racially abusing QPR defender Anton Ferdinand.
Terry, who denies any wrongdoing, spoke for the first time about Capello's departure during Chelsea's pre-match press conference ahead of Wednesday night's Champions League last-16 second leg against Napoli.
The Blues had requested no questions on England but, when asked about Capello by an Italian journalist, Terry was unable to bite his tongue.
"Quite clearly, Fabio backed me," he said.
"That comes from a relationship with myself and him, the relationship we built up.
"I stood for him on the football pitch, and he stood up for me off the pitch.
"I respect that from him, I respect him as a man and for what he did for me. Complete respect both ways."
The FA were content for Terry to remain as captain when the allegations against him first emerged and even after he was charged.
But once his trial date was set after the European Championships, they performed a U-turn, a decision Capello completely disagreed with.
The Italian's successor, currently interim manager Stuart Pearce, will be free to select Terry for Euro 2012 but not to restore him as skipper.