Barcelona superstar Lionel Messi said on Friday he felt far too emotional to face the media glare at coach Pep Guardiola's farewell announcement.

"I want to thank Pep with all my heart for everything he has given me in my professional career and personally," the 24-year-old Argentinian said on his Facebook page.

"Because of the emotions I feel, I preferred not to be present at Pep's press conference and to stay away from the press because I know they will look for the pain on the players' faces.

"It is something I decided not to show."

More than 100,000 fans clicked the 'Like' button on Messi's comment to demonstrate their support and 10,000 left comments, the vast majority backing him.

Defender Gerard Pique, who left hospital just two days earlier after a bash to the head during Barcelona's Champions League semi-final defeat to Chelsea, praised his departing coach.

"Many thanks Pep for giving us so much," he wrote on his Twitter account.

"Four years full of victories, of good times and above all lessons in football."

Only on Monday, the 25-year-old Pique had said he was convinced Guardiola would stay on as coach because of his love for the club and the profession.

However, the 41-year-old coach announced on Friday he was bringing his four-year reign over one of the greatest eras in club soccer to an end.

"Four years is an eternity as coach of Barca. Time wears everything down, I feel drained and I need to replenish," said Guardiola, who cited exhaustion as the reason for his departure.

"I cannot replenish if I coach again immediately, I don't want to."

Barcelona president Sandro Rosell appointed Francesc 'Tito' Vilanova, a former Barcelona player and Guardiola's assistant for the past four years, as the new coach.

Cesc Fabregas, who returned last year to childhood club Barcelona from Arsenal, said on Twitter: "Even though I was only with him for one year, it felt like a lot more. For me Pep was my hero as a kid."

The Spain international gave a vote of confidence to Vilanova, who came through Barcelona's youth ranks as a player before joining other sides, rejoining the Catalans as a youth coach in 2007.

"For Tito, I wish the best in this new opportunity that football has given to him. We were together when I was a kid," Fabregas said.

Players piled on the gratitude from their Twitter accounts.

"You have shown us the way," captain Carles Puyol wrote.

Agence France-Presse in Madrid