Villarreal's UEFA Europa League fixture at home to Qarabag on Thursday has been postponed after 'several positive Covid-19 cases' in the Azerbaijani club's squad.
The two teams were set to meet in the Group I at the Estadio de la Ceramica but Qarabag do not have the minimum number of players available to fulfil the fixture, a statement by the Spanish club said.
UEFA has contacted both clubs to assess the situation and find a resolution.
Villarreal are already assured of top spot in the group and progress to the last-32 of the Europa League, while Qarabag, with just one point from five games, have already been eliminated.
Villarreal won the reverse fixture, played in Istanbul because of the security situation in Azerbaijan, 3-1 back on October 29.
They are the leading scorers in the group stages, having netted 14 times in their five games so far.
Maccabi Tel Aviv and Sivasspor, who will meet in Israel on Thursday, are both able to take second spot behind the LaLiga team.