Chelsea's record £50m signing, Fernando Torres, has revealed he made up his mind to leave Liverpool midway through the January transfer window, more than a week before Chelsea's bid for him became known.

Torres was officially unveiled at his new club's Cobham training base this afternoon after completing his move from Liverpool on transfer deadline day.

Chelsea had a bid rejected for Torres four days before the end of the window but the striker had decided "10 [to] 12 days before the transfer window closed" that his future lay away from Anfield.

And he admitted he knew Chelsea would be his destination as soon as the clubs began talks. "As soon as I knew that Liverpool and Chelsea were talking about that, I told them that the decision was made," he said. "I was the first one to go to the manager and tell them."

Some Liverpool fans were seen burning Torres replica shirts when news of his £50m transfer became known, but the player said: "I can't say anything bad about (Liverpool supporters) because they made me feel really good. I understand they will be angry. I would like to explain to them all the reasons."

Hinting that his discontent dated back to the departure of other key players such as Xabi Alonso and Javier Mascherano, he said: "I was an Atlético Madrid fan. When some of the players left the club, I couldn't understand. They did the best for themselves and their families and their careers."

Torres's commitment to the cause at Liverpool had been criticised this season but he said: "I never lost my ambition. Too many people are talking about that – that's just opinions. I was playing out of form for a month."

The 26-year-old seemed unconcerned about the pressure of his price tag, a record fee between British clubs. "I have been in this situation before when I signed for Liverpool – big money, big expectation – so this is not new," he said. "I'm more than ready for the challenge."

He insisted he had a good relationship with Liverpool's caretaker manager, Kenny Dalglish. "I didn't talk with him when I left the club," he said. "I had a good relationship with him for the three weeks he was the coach."

Torres's first game is set to be against Liverpool on Sunday. Having said earlier this week he would like to score against his former club, he revealed today he would not celebrate if he found the net.

"I have big, big respect for Liverpool fans so I don't think so," he said. On the prospect of facing his former team-mates he said: "It's going to be a strange situation for me. I left in Liverpool a lot of friends. I have a very good relationship with all of them."

Torres is looking forward to linking up with Didier Drogba and Nicolas Anelka. "It's a big, big challenge," he said. "When we played against Chelsea, we were very worried about both of them."