The Spain international is understood to be attracted by the prospect of joining Hansi Flick's side, believing Barcelona offer a stronger long-term sporting project than his other potential destinations.
The right-back is reportedly keen to leave Tottenham, while Barcelona have identified him as a possible option to strengthen their defence ahead of the 2027-28 season.
However, the financial gap between the two clubs could prove decisive. Tottenham are understood to value Porro at around €70 million, while Barcelona believe a fee closer to €50 million would be more realistic.
The Catalan club are therefore reluctant to make a formal move until there is a sign that the London side could lower their demands.
Porro has also acknowledged that interest from Barcelona is flattering. Speaking to SPORT, he was asked whether the attention from one of the world's biggest clubs was a source of satisfaction.
“When one of the best clubs in the world is interested in you, or at least that's what they say, it's always good, because it probably means I'm doing my job well. You have to keep going in the same direction,” he said.
The defender was also asked about reports that Barcelona president Joan Laporta had identified him as one of his preferred targets.
He admitted that he had not been aware of those comments, but welcomed the recognition.
“It's also a compliment from him. As I said before, it's good when, for example, the president of another club that isn't mine values your work. It probably means I'm doing things well,” Porro added.
Barcelona's interest is therefore clear, but any potential transfer will depend on whether Tottenham are prepared to negotiate at a significantly lower price.
Porro's preference could help the Catalan club, although the two sides remain some distance apart in their valuation of the player.