Fernando Torres has reacted defiantly after a "difficult" debut for Chelsea by insisting the champions will learn to flourish within Carlo Ancelotti's preferred diamond formation and will continue to fight to retain their Premier League title.

The striker has joined the Spain squad ahead of their friendly against Colombia on Wednesday having hardly adjusted to life as a Chelsea player following his £50m move on transfer deadline day. His disjointed performance and 66th-minute substitution in the defeat by his former club Liverpool on Sunday provided a dispiriting start to his career in London, though Torres believes he will prosper alongside the likes of Didier Drogba and Nicolas Anelka within the champions' ranks.

Ancelotti has indicated he will persevere at Fulham next Monday with the slightly rejigged diamond formation that had struggled to break down a stubborn Liverpool side. Asked whether the system can prove successful, Torres said: "Yes, I think so. As Carlo has said, when you have good players you have to try and keep the balance, keep working on the system.

"There are a lot of good players here and a lot of possibilities and chances to play. There are still a lot of games to come and we have to be ready to play in different positions. All that matters is the team.

"It was a very difficult [debut] because Liverpool played a good game, with three at the back. We were not expecting that and maybe they took advantage of that. We didn't create enough chances to score, but we had two or three controversial chances at the end when maybe we could have had a penalty. I think the fair result would have been the draw – it was unfair to lose that game – but now we are looking forward to the next game and will keep fighting until the end. There are a lot of points still to play [for]."

Defeat represented a missed opportunity for Chelsea, who continue to languish some 10 points behind the leaders, Manchester United, despite Sir Alex Ferguson's side suffering their first defeat of the campaign on Saturday. Yet, even with 13 games remaining, Chelsea retain hope of clawing their way back into the title race with two games against United still to come. Torres will need to be at his best for those contests and his former team-mate Jamie Carragher, so accomplished in snuffing out the Spaniard's threat on Sunday, is convinced the forward will prove his worth in a Chelsea shirt.

"I don't think any of the players had a problem with him," said Carragher. "He was a great player for us, and scored lots of goals. In our opinion we had the best striker in the world. Unfortunately these things happen in football, and we now have to focus on the players that have come. You wish him well. I've played against him in training many times, and he's a fantastic player. He and Drogba are probably two of the best strikers in the world, and I'm sure Fernando will be a fantastic signing for Chelsea. No doubt about that. Good luck to him."

An object was thrown at Torres from the away section on Sunday and the Football Association is expected to ask Chelsea and Liverpool for their observations before deciding whether action is needed.

The Liverpool goalkeeper José Reina said it had been "tough" to see his friend Torres depart but added: "Football is like that, as players we come and go. You have to understand his decision; he felt it was a good opportunity to continue developing. The club has to look forward and forget Fernando. He is not here any more and we can't do anything but wish him a lot of luck."

Addressing the fans' anger towards Torres, Reina said: "It's logical that people don't understand it but I think they have to make an effort and remember what he did for the club during these past three and a half years. He scored a lot of goals, he provided many entertaining afternoons of football and that is what we have to remember, the smile that he put on people's faces in many matches."

Torres returned to Madrid to link up with the national team fit and ready to play against Colombia and hoping to find form with which to make his mark at Craven Cottage next week. "I am fine," he said. "I have had no injuries this season at all. I keep working on my form and keep improving and hopefully all the injuries are gone.

"I have to forget that and think I can play every game for 90 minutes. But it is important to be there with Spain. We are world champions so I will enjoy these three days, but I will be ready to come back as soon as possible to London to keep training and meeting all the people."