Glasgow have been forced to call off next week’s clash with Edinburgh after reporting four players have tested positive for coronavirus.
Exeter and Glasgow Warriors' Champions Cup fixtures have been cancelled after a number of Chiefs players and staff tested positive for Covid-19.
Danny Cipriani has left Gloucester with immediate effect, with the club announcing Scotland fly-half Adam Hastings will join for next season.
Exeter launched their defence of the Heineken Champions Cup by thrashing Glasgow 42-0 at Sandy Park.
Gloucester conceded the most points in their Champions Cup history as they started the new campaign with a 55-10 hammering at the hands of Lyon.
Ahead of Sunday's four Heineken Champions Cup clashes, we take a look at each club's form, team news and key players...
Glasgow fly-half Brandon Thomson missed a simple conversion with the final kick to hand Dragons a dramatic 23-22 victory at Scotstoun.
Edinburgh fly-half Jaco van der Walt will make his Scotland debut in Saturday's Autumn Nations Cup clash against Ireland in Dublin.
Glasgow have made their worst start to a league campaign in 15 years after slumping to a 27-13 defeat against Munster at Scotstoun.
Exeter Chiefs will begin their Champions Cup title defence with a home fixture against Glasgow Warriors on Sunday December 13.
Ulster beat Glasgow to maintain their 100 per cent winning start to the season, while under-strength Edinburgh saw off Cardiff Blues.
Scotland's Autumn Nations Cup hopes have suffered a major blow with news that Finn Russell and Adam Hastings have both been ruled out with injury.
Zebre stun Ospreys, Ulster edge Cardiff while Leinster have too much firepower for Glasgow in Monday's PRO14 action.
Champions Cup holders Exeter Chiefs will face Glasgow Warriors and Toulouse in the 2020/21 pool stages.
Glasgow have lost three players for Saturday's PRO14 clash away to Ospreys after one of the trio tested positive for Covid-19.
Finn Russell is back for Scotland, while Duhan van der Merwe and Oli Kebble are set for their debuts against Georgia on Friday night.
Finn Russell has been recalled to the Scotland squad for the first time since the 2019 Rugby World Cup, after a period in exile.
Oli Kebble boosted his Scotland hopes with an impressive try-scoring display in Glasgow's 20-7 victory over Scarlets.
Recap the opening round of the Guinness PRO14 as Munster beat the Scarlets late on, while Connacht beat Glasgow in Galway.
Glasgow Warriors ruined the Edinburgh fans' long-awaited return to Murrayfield with a 15-3 win in their PRO14 clash on Friday.