MADRID, Dec. 16 (Xinhua) -- COVID-19 has cast its shadow over the 18th and last round of La Liga games before the Christmas holidays, with both Real Madrid and Valencia hit by the virus.
Real Madrid confirmed that Luka Modric and Marcelo had tested positive for the virus on Wednesday, and it is possible more cases could be detected ahead of Sunday's game against a struggling Cadiz.
Real Madrid coach Carlo Ancelotti will be confident that his squad is deep enough to cover for any absences, with Fede Valverde able to step into the side for Modric if needed, while Marcelo was unlikely to start at the weekend anyway.
Valencia have been hit hardest among their coaching staff, with coach Pepe Bordalas and his assistant Patri Moreno both in isolation for the Valencia derby against Levante on Monday night.
Levante are still rock bottom of La Liga without a win all season, and their campaign went from bad to worse on Tuesday when they were also knocked out of the Copa del Rey by third-tier Alcoyano.
The round of matches begins on Friday night with Celta Vigo at home to Espanyol. Celta needed 120 minutes to beat FC Andorra in the Copa on Tuesday, and need striker Iago Aspas to be fit as they look to improve their disappointing home form.
Rayo Vallecano have no problems with their home form, as they have the best results in front of their fans in La Liga, and Andoni Iraola's men will be optimistic of another three points when they face Alaves, who sit just one place above the relegation zone.
Alaves are another side that suffered a Copa del Rey upset in midweek after a shocking performance saw them lose 2-1 to Linares.
Real Sociedad and Villarreal had no problems in the cup, with Villarreal netting seven on their visit to Atletico Sanluqueno, and Unai Emery will think his side have a chance of all three points against a rival that has lost their last three league matches.
FC Barcelona should be able to put a temporary halt to their crisis when relegation-threatened Elche visit the Camp Nou, although Xavi Hernandez is still handicapped by an injury list that includes Memphis Depay, Jordi Alba, Pedri, Ansu Fati and Sergi Roberto.
The weekend's biggest game is in the Sanchez Pizjuan stadium, where second-placed Sevilla entertain fourth-placed Atletico Madrid.
Atletico are without Antoine Griezmann, Koke, Sime Vrsaljko and central defenders Jose Gimenez and Stefan Savic, with the loss of the last two the biggest problem for Diego Simeone in the wake of last weekend's defeat to Real Madrid.
On Sunday, Granada, who seem to be picking up after a poor start to the season, entertain Mallorca, before Athletic Bilbao face an in-form Real Betis.
Athletic have struggled to score goals, with just 13 all season, with last weekend's defeat to Sevilla highlighting their problems in front of goal, as they created and missed a hatful of chances.
Betis, meanwhile, have never won in the new San Mames Stadium, but travel after thrashing Real Sociedad 4-0 for their fourth consecutive league win.
Sunday also sees Getafe host Osasuna, with the home side looking to confirm their improvement under Quique Sanchez Flores by climbing out of the relegation zone. Enditem