Connacht's home Pro14 game against Ospreys scheduled on Saturday has now been postponed.
The decision follows after one player in the Welsh regional side squad returned positive for Covid-19 in the latest round of testing.
"Having considered all the available evidence, the PRO14 Rugby Medical Advisory Group has deemed that this fixture cannot go ahead," a statement from Pro14 read.
The fixture also becomes the second game in Round 8 of the tournament to be postponed due to Covid-19 after Scarlets v Leinster match that was scheduled at Parc y Scarlets stadium on Sunday with both the matches expected to be rescheduled at the start of next year.
Meanwhile, Benetton Treviso squad returned all negative result having played against Ospreys previously which meant their fixture against Dragons will take place as schedule on Sunday.
Connacht are at third place in Conference B with three wins from five games while Ospreys are third in Conference A with three victories from seven matches.