Dani Alves was cheered by a crowd of more than 10,000 as he was introduced to Barcelona fans again, saying he insisted on returning to help put the Catalan club back on track.
The 38-year-old Brazil defender said he will be ready to fight for a starting spot when he is eligible to play in January.
“I come to compete, not just to spend time and live in Barcelona,” Alves said. “I come to play and to fight for a spot on the team. I’m not back just because I have a very good relationship with the coach or the president. With hard work I’ll try to contribute any way I can.
"Once again, I'm here. If you remember the last time that I took this microphone, it was to say that I didn't know when my dream would end.
"But I'm here again, still living the dream. You make me feel special, like one of you. This is something that is never is going to change.
"Long live Barca, long live Catalunya."
Alves was without a club since leaving Brazilian team Sao Paulo in September. He signed a contract with Barcelona until the end of the season, the club's first campaign without Lionel Messi in nearly two decades.
A crowd bigger than the one that welcomed new coach Xavi was at Camp Nou as club president Joan Laporta introduced Alves, who took off the sandals he was wearing before stepping on to the field.
“I had to get serious with the president and insisted that I wanted to come back,” Alves said. “I knew I could help. Then I got a call from Xavi and everything after that was very easy. When you want something you can make it happen. Money is not the most important thing. It's not time to think about money. It's time to return to help Barca. Everything else is secondary.
"I haven't come here on holiday. I came here to compete. I wasn't born to be second. I want to be first. Always. So I'm going to fight like I always did. The expectations are high. My age is only a number."
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Alves arrived as a free agent but details about his salary were not released by the club.
Barcelona have been enduring one of their worst spells amid unprecedented financial difficulties that began before the coronavirus pandemic.
Xavi, Alves' former teammate, took over the club after Ronald Koeman was fired because of the team's poor results this season. Barcelona are ninth in the Spanish league and got off to a bad start in its Champions League campaign.
Alves was part of Barcelona’s greatest era from 2008 to 2016, helping the club win 23 titles, including three Champions League and six Spanish league titles. He scored 23 goals in 391 games for Barcelona before leaving to play for Juventus, Paris Saint-Germain and then Sao Paulo, where he fell out with club officials over money he was owed.
Alves said his goal is to play with Brazil at next year's World Cup, and that will depend on his performances with Barcelona.
Laporta did not dismiss the return of other former greats, such as Iniesta and even Messi, who left for Paris Saint-Germain because of Barcelona's financial situation.
“I don't rule it out,” Laporta said. “It happened with Dani Alves. Age is only a number. I can't predict the future, they are with other clubs, but in life we never know what can happen.”