- Barcelona coach Tito Vilanova suffers tumor relapse but will stay in post
- Vilonova has surgery in Barcelona before starting chemotherapy and radiotherapy
- When Vilanova was assistant to Guardiola between 2008 and 2014, Barca won 14 trophies
- Under Vilanova, Barca have won 23 of their 27 matches this season
Barcelona soccer coach Tito Vilanova is recovering in hospital following surgery to remove a regrown cancerous tumor.
The Spanish league leaders' website reported on Thursday that the operation "went ahead according to schedule."
"The manager's post-surgery recovery will determine his stay at hospital. In line with the patient's wishes, please respect the privacy and confidentiality of the process," the club said.
In November 2011, Vilanova had a tumor removed from his parotid gland -- which is at the back of the mouth -- when he was assistant to his predecessor as Barca boss, Pep Guardiola.
That operation was thought to have been a success and when Guardiola went on sabbatical, Vilanova took over as coach of the team -- seemingly in good health, but more cancerous cells have been discovered.
Vilanova is expected to be hospitalized for three to four days after his surgery and will then have chemotherapy and radiotherapy treatment lasting around six weeks, according to Barca's website.
Club doctors have said he will still be able to work while his treatment takes place and there are no plans for him to step down. His assistant Jordi Roura will take charge for the weekend clash with Valladolid.
At a press conference, club president Sandro Rosell said: "I want to thank everyone for their support on behalf of the team and Tito. We have complete confidence in the team. The club is very strong and very united, we're capable of overcoming adversity.
"Tito is strong, very strong, he's shown us that and we're convinced that he'll be back with us soon."
Vilanova had told the Barca website earlier this week: "Being a head manager is difficult, but being an assistant manager isn't easy either. I would say it's more difficult to be an assistant manager than it is to be a head manager."
Under Vilanova's guidance, Barcelona have been unbeatable in the Spanish league -- dropping just two points -- and hold a nine-point lead over second-placed Atletico Madrid, with close rivals Real Madrid 13 points behind the Catalan side.
Real responded to the news by expressing their support for Vilanova, in a statement on their official website.
They said: "Real Madrid wish to express their heartfelt support to Barcelona coach, Tito Vilanova, to whom we wish a prompt recovery. Real Madrid extend this support to his club and family."
Barca also finished top of their European Champions League group, suffering just one defeat in six matches.
Key to their success this season has been the number of goals Lionel Messi has scored, with the Argentine netting 25 times during the current campaign and 90 times during the calendar year.
As a youngster Vilanova was at Barcelona's youth academy -- La Masia -- with Guardiola, though unlike the former Barca captain he failed to graduate to the first team.
Vilanova went on to play for some of Spanish football's lesser known clubs -- Figueras, Celta, Badajoz, Mallorca, Lleida, Elche and Gramenet -- before retiring as a player in 2002 and turning to coaching.
When the 44-year-old Vilanova was appointed, Barca sporting director Andoni Zubizarreta argued it was "a logical decision" because he "represents the same style of play and the same philosophy."
"Tito has been working here with us, so why not Tito? He puts in all the hours until he sleeps and he has the personality that we need to lift us. He's different to Pep, but Tito's the one," said Zubizarreta.
"We've always looked in house. We have Tito -- it's simple. We needn't go out on the market."
Between 2008 and 2014 with Guardiola and Vilanova as coach and assistant, the Catalan club won 14 trophies, including two Champions League titles.
That recent success has been fostered on a tradition of developing their own players at their youth academy.
"Our style of play is so different from the rest of the teams that it's just easier to send out a guy that grew up playing our style football," said Vilanova.
"These players train their whole lives as Barca players, with the Barca system. If they play for the first team, it's because we think we can win with them on the pitch."
Since taking charge of Barca, Vilanova has won 23 of his 27 matches in all competitions, suffering just two defeats.