Barcelona coach Tito Vilanova on Thursday vowed a swift return from cancer surgery that may sideline him for six weeks in a shock for the Spanish league leaders.
"I will be away for a while but I will be back soon," Barcelona sports newspaper Mundo Deportivo quoted Vilanova as telling his players the night before he went in for surgery to his salivary gland.
A newspaper close to Barca, Sport, reported that the operation had been completed on Thursday morning and that Barca would give an official update later.
"I think that all of us in Spain without exception, regardless of ideology and even of sporting preference, are with Tito, who is being operated on right now," Spain's Sports Minister Jose Ignacio Wert told radio station COPE earlier.
Vilanova, 44, has led Barcelona to their best league start ever but the club said he will be in hospital for four days and then need up to six weeks of chemotherapy or radiotherapy.
"We will have to try to go on as normally as possible but there will not be total normality because Tito is the coach and now for a few weeks he will not be there," the club's president Sandro Rosell said late Wednesday.
"Tito is very strong and we are convinced he will come back to us soon," he insisted at a news conference, as players including Xavi Hernandez and Andres Iniesta sat by solemn-faced.
A six-week lay-off would mean Vilanova may return just in time for Barcelona's last-16 tie in the Champions League, which will be against AC Milan in mid-February, the draw revealed on Thursday.
Before the draw in Nyon, Switzerland, UEFA secretary-general Gianni Infantino said in Catalan: "Tito, we are all with you."
The surgery came at a dramatic moment for Barca, flying nine points high at the top of Spain's La Liga while their fierce rivals and title holders Real Madrid are suffering a malaise.
Jose Mourinho's Real are 13 points adrift in third place and rattled by reports of internal squabbles. Atletico Madrid are in second place, nine points behind Barcelona.
Barca's sporting director Andoni Zubizarreta said assistant coach Jordi Roura would stand in for the time being, acting as coach when the side travels to Valladolid for Saturday's league game.
Barcelona gave no indication Thursday of when it would next give details of Vilanova's progress.
Messages of support poured in from sporting stars and even occupied the front pages of the fiercely partisan Madrid sports press.
"We're all with Tito," said Marca, the leading pro-Real daily.
Zubizarreta rejected speculation that Barcelona's previous coach Pep Guardiola who left last season would step back in.
"Tito is the coach and continues to be the coach. Jordi Roura will be in the dugout at Valladolid but the trainer is Tito," he told a news conference.
Real Madrid joined various sporting figures in Spain and abroad in wishing Vilanova well.
"Tito, everyone is behind you to beat this -- the strength of football and people. It's impossible you will lose this match," Real skipper and Spain international keeper Iker Casillas wrote on his Facebook page.
Vilanova has been Barca manager since the departure of his long-time comrade-in-arms Guardiola in April.
Vilanova underwent an operation to remove a tumour on his parotid salivary gland on November 22, 2011 and was back at work as Guardiola's deputy just two weeks later.
The club said doctors had detected that the illness had returned to that gland.