MADRID, Dec 16 (Reuters) - LaLiga leaders Real Madrid will play at home to Cadiz on Sunday while fighting a COVID-19 outbreak with seven positive cases already confirmed from the first team - six players and a coach. After Luka Modric and Marcelo tested positive on Wednesday, the club said on Thursday that Gareth Bale, Marco Asensio, Andriy Lunin and Rodrygo plus assistant coach Davide Ancelotti - manager Carlo Ancelotti"s son - had also got the virus. Since all seven are vaccinated they must quarantine until they test negative according to Spanish government protocol. They will not be available for Sunday"s game at Cadiz and could also miss Wednesday"s LaLiga match at Athletic Bilbao. It is a big blow for Real, who are eight points clear of second-placed Sevilla, 13 above Atletico Madrid in fourth and 18 in front of eighth-placed Barcelona, having played a game more. Croatia midfielder Modric, 36, has been one of best players in LaLiga this season, while forwards Asensio and Rodrygo have alternated as starters alongside Karim Benzema and Vinicius Jr. It could provide an opportunity for Eden Hazard get back in the starting team after his struggles with injury and poor form since arriving from Chelsea in 2019. The biggest game of the weekend will be played in Andalucia, where Sevilla welcome Atletico Madrid on Saturday. Sevilla, who have only lost two LaLiga games this season, won 1-0 at Athletic Bilbao last week and are making a case to position themselves as the strongest contenders to Real"s dominance as mid-season approaches. Atletico lost 2-0 in the Madrid derby against the leaders and are in desperate need of a win to rebuild their morale. Far from title contention but not from the news, Barcelona entertain Elche with coach Xavi Hernandez trying to hold his team together in what has been a nightmare season son far. "We are in a negative spiral and we need to find a way to break it," Xavi said after last weekend"s draw at Osasuna. On Wednesday, Xavi and his players went to Camp Nou to pay tribute to Argentine team mate Sergio Aguero, who announced his retirement from football due to a heart condition. read more It was another setback for a Barca side who have won six of 16 league games this term and went out of the Champions League at the group stage for the first time in almost two decades.