Argentine star Lionel Messi has not forgotten to say goodbye to his friend and former teammate at Barcelona Sergio Busquets after the latter announced that he will leave the Blaugrana at the end of the current season after spending 18 years with him.

The Pulga and Busquets shared great moments in Barcelona, won all the titles, and were an essential part of Barcelona's best team in history.

The relationship of the players went beyond the green rectangle. Despite Messi's departure to Paris and Busquets staying at Barça and the distance between the two cities, the friendship between the two former teammates was strengthened and Messi and Busquets were seen having dinner together at a Barcelona restaurant.

That's why, after such an important day for the former Spain international, his friend and former teammate Leo Messi did not miss the opportunity to send a sincere message in appreciation of Bossy's career at Barcelona, the two stars won everything together but were also together in the most difficult moments.

On his official Instagram account, the "flea" wrote the letter and attached it to photos of his meeting with Busquets.

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"On the pitch you were wearing the number (5), but in reality you are the number (10) players and human beings. I wish you the best in your new phase for you and your whole family. Thank you for everything you've done on and off the pitch, there were many moments we spent together, many good moments and others that were complicated. It will remain forever."

Busquets, 34, began his youth career at Barcelona in 2005 before making his first-team debut in 2008.

The former Spain international has captained the team for the past two seasons in recognition of his outstanding role with the club.

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Busquets helped Barcelona win La Liga titles, 7 Copa del Rey titles, 3 Champions League titles and 3 Club World Cups.

Busquets said on Instagram on Wednesday: "I felt very proud to wear the armband but everything has an end."

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Busquets, who retired from international football last year, has made more than 700 appearances for Barcelona and holds the record for appearances in top matches in Spain more than any other player, making 48 appearances against rivals Real Madrid.

Busquets could add another league title to their achievements this season, with Barcelona leading the standings by 13 points from their nearest pursuers with five games to go.

Spanish media reported that Busquets accepted an offer from Saudi club Al Hilal.