BARCELONA/PARIS (REUTERS) - Barcelona fans gathered outside Lionel Messi's house on Monday (Aug 9) and spoke of their sadness at the club's greatest player leaving after 21 years, while Paris Saint-Germain fans eagerly awaited his arrival in the French capital.

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

"I feel devastated," said Cristian Garcia, wearing a Barca shirt with Messi's name and No. 10 on the back outside the player's home.

"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, 34, said he had agreed to a 50 per cent 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 debts, which total more than €1 billion (S$1.6 billion).

La Liga said last Wednesday it had secured a private equity injection of €2.7 billion from firm CVC, with the funds to be shared among the clubs in return for 10 per cent of the league's revenue.

It had been believed this would allow Barcelona to get the Messi deal done, but after Real Madrid rejected the proposal and said they would take legal action against La Liga, Barca also came out against it.

"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.

Legal complaint

One Barcelona fan was filing a legal complaint in Paris accusing the French football authorities of failing to enforce their own financial fair play rules in order to help PSG become a force in European football, a copy of the complaint seen by Reuters showed.

PSG and the French football league did not immediately respond to e-mailed requests for comment.

French newspaper L'Equipe reported on Sunday that Messi would travel to Paris on Sunday or Monday for a medical check-up and to finalise a deal with the Qatar Sports Investment-owned club.

Spanish newspaper Marca reported that PSG had formally sent their offer to Messi on Sunday morning.

While Messi did not confirm he would definitely join the Parisians, he said his plans were to carry on playing as long as possible, adding he still harbours ambitions to win another Champions League trophy.

"We're waiting for a legend, the legend that is Leo Messi," said PSG fan Mehmet Sen, who had been waiting at the gates to Paris' Le Bourget airport since 2am for a glimpse of the star.

There were no signs of movement around Messi's house in the hills of the wealthy Barcelona district of Castelldefels, however.

Youngster Jonas Romero said outside the house that 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."