Mata, who became the first member of the squad to comment on Villas-Boas' departure when he wished the Portuguese luck, insists Chelsea still have what it takes to win some silverware this campaign.
Chelsea's players have been accused of getting Villas-Boas the sack following widely publicised claims of dressing-room unrest at Stamford Bridge, with former Blues boss Luiz Felipe Scolari claiming the same thing happened to him in 2009.
The Brazilian manager, who is now in charge of Palmeiras, said in a press conference that he believed some key players have huge influence with owner Roman Abramovich and also warned "it will be hell for whoever succeeds" Villas-Boas.
However, Mata, who was one of the first signings of Villas-Boas' tenure, claims his team-mates are ready to unite behind caretaker boss Roberto Di Matteo and snatch fourth place in the Premier League and keep their FA Cup and Champions League dream alive.
"I think we have to start again,'' Mata told Chelsea TV. "We are not in a good moment, we are not in a good run of results, but we all want to change it. I think we are ready to change it.
"We have a very good squad and we have two months to achieve our objectives in the Premier League, in the FA Cup and Champions League.''
Di Matteo, who played for Chelsea from 1996 to 2002, has been promoted from assistant manager and will be in charge until the end of the season. His first test will come against Birmingham in the FA Cup on Tuesday night.
Former Chelsea midfielder Eddie Newton has joined Di Matteo's backroom staff, while Jose Mario Rocha and Daniel Sousa have left the London club.