Barcelona boss Tito Vilanova has stepped down with immediate effect after suffering a tumour relapse, according to reports in Spain.
Vilanova underwent a successful operation to remove a tumour found on his parotid gland - the largest of the human salivary glands - last November when he was Pep Guardiola's number two.
But the 44-year-old, who took charge in the summer following Guardiola's departure, has now suffered a relapse and will have further surgery.
Barcelona are expected to appoint a temporary replacement while Vilanova undergoes treatment, with Guardiola being heavily linked with a return to the Nou Camp.
Vilanova has guided the Catalan club to their best ever start to a season, with Sunday's win over Atletico Madrid making it 15 victories out of 16 La Liga games.
Barcelona will make an announcement later today with regards to the Spaniard's health.
A statement from the club read: "Barcelona announce that it is has suspended the press conference from president Sandro Rosell planned for midday. As well as that, the media Christmas lunch has been cancelled.
"Later today the club will issue a further release. Until that time we will not make any announcement about this matter. We regret any inconvenience this decision may cause."