Dani Alves is ready to begin "the most important challenge" of his career when he makes his second debut for Barcelona in Tuesday's exhibition match with Boca Juniors.

The 38-year-old re-joined the club on a free transfer last month following his departure from Sao Paulo in September over a contractual dispute.

Alves, who played 391 times for Barca in his first trophy-laden spell at Camp Nou, cannot be officially registered for the Catalan giants until the January transfer window opens.

However, the Brazil international is in line to represent Blaugrana on Tuesday when they face Argentine giants Boca Juniors in the Maradona Cup in Riyadh.

Speaking at a pre-match news conference on the eve of the friendly, Alves said: "I'm feeling nervous after not being able to play and represent the club for so long.

"The most important challenge of my career has come, because of how the situation happened and the position the club is in.

"But challenges are for those who do not fear them. We will all do our best for this club and for this badge."

Alves won 23 trophies in eight seasons with Barca before departing in 2016 for spells with Juventus, Paris Saint-Germain and Sao Paulo, where he spent two years.

The club the veteran full-back has returned to five years on is a long way off competing for major honours. 

Barca exited the Champions League at the group stage last week and are eighth in LaLiga after 16 matches, but Alves is hopeful he can help the Catalans return to the top.

"We're used to seeing Barcelona at the top but we know there's a problem," he said. "We cannot hide from it, but instead look for a solution as soon as possible.

"When I arrived the first time a transformation had to be made. The situation is different but it's done and we will write a new chapter to get Barca where they are used to. 

"We have to recover the winning feeling because we live for winning. We have to change the streak. In football, there are good and bad streaks, though this is lasting a bit longer."

Barca have named a 28-man group for the meeting against Boca, with Alves joined by the likes of Gerard Pique, Ousmane Dembele, Philippe Coutinho and other first-team stars.

The timing of the game, with league matches against Elche and Sevilla to come over the next eight days, has raised questions.

But while Xavi accepts the distance travelled is not ideal, he believes it is important to respect Maradona, who died from a heart attack aged 60 last November.

"These are club circumstances and is something that was previously agreed," he told reporters in Saudi Arabia. "For us it's an honour to be here representing Barcelona.

"We are paying homage to one of the best players in history. It's an honour and a privilege and it will be an emotional occasion."

Hinting at changes to the side that started the 2-2 draw with Osasuna on Sunday, Xavi added: "It will be a test for the players that don't usually play and a chance to see players that haven't played so much. We want to be at our best."