Soccer:Cesc Fabregas spoke of facing the challenge of his life after completing his move from Arsenal to Barcelona. The Spaniard has signed a five-year contract with the European champions after passing his medical at the Camp Nou, ending an eight-year association with the Gunners, for whom he left Catalonia as a 16-year-old.

After penning his contract Barca's new number four was presented to the Barca fans.

"For me it's a special day," he told Spanish media. "I'm returning home. I know that the Arsenal fans will be disappointed with my exit from the club, but I'm here to face an incredible challenge, the challenge of my life."

Fabregas joins a Barca side that have won 10 trophies since Pep Guardiola took charge in 2008, including three successive Primera Liga crowns and two Champions Leagues, but he chose first to praise his former manager Arsene Wenger.

"I'll never have enough words to thank him for all he's done for me," he said. "I'll never forget him. I don't think he has such a good image here, he has been portrayed as something he's not, in my opinion. If today I am here with you then it's greatly due to him.

"I can't express my admiration for him strongly enough, I owe it to him that I am here."

Fabregas added: "To get the number four shirt is very special. I know there has been a debate about whether Thiago (Alcantara) should have it but I'm very pleased to be able to wear the number four."

Fabregas said of his Arsenal career: "It's been a terrific experience. I come here with great humility because I know I have a lot to learn and I can learn a lot from this coach and this great team. I've played with two of them (Lionel Messi and Gerard Pique) since I was 13 and many of the others since I was 18 (with Spain) so I know them very well.

"I know I can enjoy it and make a contribution. I'm going to try very hard to make this team even more competitive and strong."

Wenger has challenged his Arsenal squad to prove it can cope without Fabregas.

"What is important is to focus on our targets and we wish good luck to Cesc, who is a great player, one of the best players in the world. Life goes on and we want to show we have the needed desire and strength to deal with the situation," Wenger told a news conference ahead of Tuesday night's Champions League play-off first leg against Udinese.

"Yes, we lost a world-class player and we are sad about it. We did fight to keep him, but in the end we have as well to respect the desire of the player. This club is 125 years old this season and many big players have left the club and the club went on.

"We want to show that we have the strengths and unity to fight as we ever did at this club."

Wenger maintained for Fabregas, the lure of Barcelona was just too strong - and is why Arsenal did not put their captain on the open market, where he would have fetched a much higher fee.

"To get the best out of a player, he needs to be completely committed to where he is. Cesc wanted to go back to his home city," the Arsenal boss added. "If you understand one thing, it is Cesc did not go for financial reasons, or that he did not love this club - Cesc went because he was desperate to play for his home town club, where he was educated.

"It is very difficult to resist that."

Fabregas insists he is ready to play the second leg of the Spanish Super Cup clash with Real Madrid on Wednesday if called upon following last night's 2-2 first-leg draw in the capital.

"I didn't see the first leg as I was flying over," he said. "But physically I'm fine and ready for everything. It's not my decision whether to play or not. I'm going to work very hard as always and enjoy it. I will give everything to make this club better."