Messi, 35, only has a deal with Paris Saint-Germain until the end of June, and there is currently widespread speculation surrounding his future.
The World Cup winner is believed to be considering all options in the table, which include signing another deal at PSG, while there is thought to be interest from the MLS and Saudi Arabia.
Barcelona have also been heavily linked with a move for the forward, who departed Camp Nou on a free transfer in the summer of 2021 due to the Catalan outfit's financial problems.
Pique left Barcelona towards the end of last year, but he remains a huge supporter of the club, and the former defender has talked up a return to Camp Nou for his former teammate.
"If he is still motivated, it'd be normal to stay in Europe and then Barcelona can enter his plans," Pique told RAC1. "Or maybe he will go to MLS.
"For Barcelona fans, who know how he has made us feel, it would be a great feeling for all of us. Only he knows what to do with his future.
"I think the World Cup was the great dream he had, the title he was missing to be considered the best in history. From now on, everything he decides is more a personal matter of where to find happiness."
Messi starred for Argentina at the 2022 World Cup, scoring seven times and contributing three assists at the competition, including a brace against France in the final, which the South Americans won on penalties.
Despite interest from the MLS and Saudi Arabia, there have been suggestions that the forward wants to spend at least one more season in European football.
Messi has scored 29 goals and registered 32 assists in 65 appearances for PSG, including 18 goals and 17 assists in 31 appearances during the 2022-23 campaign.
The capital giants are in a strong position at the top of the Ligue 1 table, sitting 10 points clear of second-placed Marseille, but they were knocked out of the Champions League by Bayern Munich last week.
Inter Miami head coach Phil Neville recently talked up a potential move for Messi, while the forward suggested in a recent interview that he could sign a new deal in Paris.
Barcelona's financial problems could ultimately prevent them from putting together the package required to bring Messi back to Camp Nou this summer.
However, the Catalan outfit's head coach Xavi recently said that the 'doors are open' for Messi to return to the club at the end of the campaign.