The footballer explained in an interview with Sky Sports how his arrival at Barca was forged.
It wasn’t until the end of the 2003-04 season that Larsson finally decided it was the right time to move on from Celtic. There were 28 clubs trying to land his signature.
At 32, time was not on his side, but he wasn't in any rush. Larsson didn’t want any negotiations until after Euro 2004. Sweden was his priority.
But a few days before the tournament, a call from his wife changed that.
"She told me Barcelona were interested in me," says Larsson. "I told her they’re going to have to wait."
His wife was concerned. ‘I don’t think they’re gonna wait…’
Larsson asked her to handle the negotiations with his agent Rob Jansen. ‘I don’t want to know anything,’ he told her. ‘You sort it out and once everything is finished here I can talk to them. But I want to focus on Swedish national team.’
Partnering Zlatan Ibrahimovic up front, Larsson scored three goals in four games to take them to the quarter-finals. Defeat to Holland left a sour taste, but there was no time for self-pity.
"I had a terrible hangover because we lost on penalties," he says. "I wasn’t too pleased about that but I had to go to Barcelona to do the medical two days after. I did that, and then the press conference. Then I was a Barcelona player."
Larsson's head should have been spinning. "At that age you know what it takes," he says.
Walking into a changing room containing Xavi, Andres Iniesta and an emerging Lionel Messi didn't bother him.
It helped that Larsson had been Ronaldinho's idol since the 1994 World Cup - "he saw my dreads and he liked it”.
"The other players are going to test you out a little bit because it's a hierarchy," he says. "But they saw straight away that I could play and that I was someone that they could get something out of.
"Know that you're good, and know why you're good - and keep doing those things. I've seen a lot of good football players that after a while they stop doing the things that made them good footballers and it's downhill from there.”
Larsson held his own. He scored 19 goals in 59 games across two seasons.
His defining moment would be his final act. He came off the bench in the Champions League final to assist both goals as Barca came from behind to beat Arsenal at the Stade de France. "He changed the game," said Thierry Henry after the match.
At 34, Barcelona offered Larsson another year.
"But I wanted to go home to Sweden," he says.