Barcelona coach Tito Vilanova must have surgery Thursday and six weeks of treatment after suffering a cancer relapse, the Spanish league leaders said. Vilanova, 44, has led Barcelona to their best league start ever but he must now undergo weeks of further care for cancer in his salivary gland, the club said Wednesday. Doctors monitoring him following a cancer operation a year ago detected \"an extension of his condition which will require surgery\" on Thursday plus chemotherapy or radiotherapy for \"about six weeks\" a club statement said. It said that \"depending on how he develops, he could combine the treatment with his working life\" -- but the club\'s president Sandro Rosell at a news conference later appeared to think Vilanova would be out for weeks. \"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,\" Rosell said. But he insisted: \"Tito is very strong and we are convinced he will come back to us soon.\" 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. 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. \"What we have to do is pick ourselves up and keep on working.\" The news came at a dramatic moment for Barca, flying nine points high at the top of 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. Real Madrid joined various sporting figures in Spain and abroad in wishing Vilanova well after Spanish media reported the news. \"Real Madrid wishes to express all its support, love and affection for Barcelona\'s coach Tito Vilanova, to whom it wishes a quick recovery,\" it said. \"Real Madrid extends this support to his club and all his family.\" Online message site Twitter buzzed with messages from sporting figures including Spanish tennis champion Rafael Nadal, who tweeted: \"All my strength and support to Tito Vilanova. We are with you to overcome this.\" 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 gland -- the largest of the salivary glands -- on November 22, 2011 and was back at work as Guardiola\'s deputy just two weeks later. One of the world\'s most successful football teams, Barca are riding high largely thanks to Argentine hitman Lionel Messi, who has taken his goal tally for the calendar year to a record-breaking 90. Vilanova played only briefly as a professional in Spain\'s top flight, notably with Celta Vigo, before turning to coaching at the end of his career and finding his way back to the club of his youth. He came through Barcelona\'s youth ranks but after failing to break into the first team he continued his playing career with lower league clubs before retiring in 2002. He rejoined the Catalans as a youth coach in 2007 and was promoted to first team duties, working alongside Guardiola, for the 2008-2009 season, by the end of which the team had won six major trophies including the Champions League. Wednesday\'s announcement overshadowed the news that Barcelona\'s defender Eric Abidal returned to training with his teammates for the first time since having a liver transplant in April. Vilanova was not present at the training session.