Barcelona fans gathered outside Lionel Messi's house on Monday eager for a glimpse of the club's greatest ever player and spoke of their sadness at the Argentine leaving the club after 21 years.

A tearful Messi on Sunday bid farewell to the club he has spent his entire career at and said he was talking with French club Paris St Germain over a possible move.

"I feel devastated," said Cristian Garcia, wearing a Barca shirt with Messi's name and number 10 on the back.

"To see a player that I have always followed, who is an example for me, to see him leave now brings me a lot of pain."

Messi said he had agreed a 50% pay cut in order to stay at Barca and sign a new contract but was unable to finalise the deal due to the Spanish league's financial control rules and the club's huge debts.

"I don't think the club has done enough to make him stay, I think it was in the club's hands to make him stay, beyond the money," said Barca and Argentina fan Gonzalo Moreno.

Messi said on Sunday that PSG was "a possibility" but that he had not yet signed any deal. French media have reported that he is on the verge of doing so, however.

There were no signs of movement around his house in the hills of the wealthy district of Castelldefels where he has made his home with his wife and three sons, although the player was expected to fly to Paris within a day or two.

Youngster Jonas Romero said he was "waiting to see if we can see Messi before he leaves for PSG,", adding that he wanted the player to sign his shirt and take a picture with him.

Another fan, Saul Moreno, added: "I don't want Messi to go to PSG, but I know he's going to go."