Portuguese top-flight club Belenenses, decimated by a Covid-19 outbreak, asked Thursday for their next match to be postponed after last weekend's game with Benfica was called off when they were reduced to just six players.

"It's urgent that the league postpones the match between Vizela and Belenenses (on Monday) for reasons of force majeure," the club said in a statement sent to AFP.

Belenenses started with only nine players, including two goalkeepers, against Benfica. They trailed 7-0 at half-time, with the match stopped three minutes into the second half after three players suffered injuries.

Around 20 cases of the Omicron variant have been detected at the club, the first in Portugal of the new coronavirus strain according to the country's national health institute (INSA).

The squad and coaching staff have since been put into isolation.

Belenenses president Rui Pedro Soares said the game last Saturday was a "disgrace" and criticised the league for effectively forcing the club to play, under threat of being deducted points.

Benfica president Rui Costa described it as a "black page for Portuguese football".

Portuguese league officials met the following day to discuss the controversial fixture and whether any disciplinary action should be taken against Belenenses.

A league official told local media he had been in contact with Soares but denied receiving a "formal request" for the match to be rearranged.

On Wednesday the league called off a fixture between Tondela and Moreirense after six players for the home team tested positive for the virus.

However Friday's clash between Benfica and reigning champions Sporting will go ahead as planned. Benfica players all returned negative test results following the game against Belenenses.

Sporting will be without their captain, Uruguayan defender Sebastian Coates, due to a Covid infection.