Ronald Koeman proclaimed Lionel Messi to be the "best player in the world" after it was confirmed the Barcelona legend will be leaving the club.
Messi enjoyed an outstanding career at Camp Nou, scoring 672 times in 778 appearances, but his time with the LaLiga giants ended abruptly this week due to Barca's dire financial situation.
The six-time Ballon d'Or winner was expected to sign a new contract, having become a free agent on July 1, before Thursday's announcement shocked the football world.
Koeman, who managed the forward during the 2020-21 campaign, joined a host of football's big names in paying tribute to Messi.
"Still hard to understand that you will not play for [Barcelona] anymore," the head coach wrote on Instagram. "Thanks for everything you have done for our club. I really enjoyed the full season we worked together.
"I am impressed with your work ethic and desire to win. It makes you the best player in the world. For now, I wish you and your family the best!"
With Messi expected to move to Paris Saint-Germain, Koeman must prepare for life without the four-time Champions League winner.
Memphis Depay and Antoine Griezmann will have incredibly large shoes to fill in the 2021-22 campaign, while Barca players past and present used social media to praise their former team-mate.
Gerard Pique, who won the treble with Messi in his first season back at the Catalan club, posted on Instagram that "nothing will ever be the same again" following the end of an era.
"Now you are leaving, but I know that one day you will come back," the centre-back continued. "There are pending things to do. Have fun, enjoy wherever you go and keep winning as only you know how to do. Here we will miss you. I love you Leo."
Luis Suarez, formerly part of the formidable trio with Messi and Neymar, pipped Barca to the title with Atletico Madrid last term but he too revealed his admiration for the "best player ever".
"I will always be grateful for how you received me since I arrived because of what a great human being you are," Suarez wrote.
"Proud to have shared thousands of wonderful moments at [Barcelona] and to be lucky to have played with you. I sincerely hope that what happens in the future is the best for you and your family. I love you so much."
Despite only playing for two campaigns with Messi, Barca youngster Ansu Fati used his Instagram account to say farewell to his captain.
"All the boys who come to the Masia dream of being able to play with you, I feel lucky to have fulfilled it," Fati posted. "I wanted to thank you these two years for your gestures of affection towards me and for everything I learned.
"[Messi] my family and I will always be eternally grateful, I wish you and yours all the best."