Barca's secret trick to get Messi back

It's no secret that Barcelona are looking to bring back their club legend. Leo Messi will be out of contract with PSG this summer and his former club want him to return.
Coach Xavi Hernandez admitted as much, but recognised that ultimately the decision lies with the player himself: "It's up in the air. It depends on many things. There is not much more I can say. Leo is a spectacular footballer. He is a friend. From there, it depends on many things, but above all on his intentions and what he wants."
Although Messi played several seasons with the Spanish team, this time around they are competing with lucrative offers from the MLS in the USA and clubs in Saudi Arabia. But according to 'Mirror Football', the Catalans believe they can offer Messi something that will bring him home.
The outlet reports that Barcelona have made it clear they would offer the Argentinian the captain's armband should he return. Messi was the team's skipper before he left, and he would return as Sergio Busquets is leaving, which sees the captaincy vacant.
Messi's team have confirmed that the star is waiting for the end of the season to make his decision - will this be the final factor in his decision?