Exeter’s defence of their Champions Cup title is under threat after a Covid outbreak at the club led to two of this weekend’s European matches being cancelled, including their trip to Toulouse. Glasgow – beaten by Exeter on Sunday – have also had their match against Lyon cancelled, plunging the competition into chaos. The Chiefs have confirmed that because of a number of positive cases among players and staff – believed to be in double figures – they are unable to fulfil Sunday’s fixture in Toulouse. If the French side are awarded a 28-0 bonus-point win by the tournament organiser, European Professional Club Rugby, then Exeter’s chances of reaching the knockout stages would be greatly diminished. Either way, the competition has been denied one of the ties of the pool stages and a rematch of one of last season’s semi-finals. The matches cannot be rescheduled and EPCR has said it will form committees to determine the results but, given the outbreak has occurred at Exeter, a win for Toulouse seems the most likely outcome. In September, Castres were forced to forfeit last season’s Challenge Cup quarter-final against Leicester after an outbreak of four Covid cases. With a one-off format where teams play only four matches and the top four from two pools advance to the quarter-finals in use, Exeter would almost certainly need bonus-point wins from their remaining two matches and even that might not be enough. Glasgow, meanwhile, are also unable to fulfil their fixture against Lyon because 20 of the 23 players involved in the 42-0 defeat at Sandy Park are having to self-isolate. The Warriors would appear to have a better defence against forfeiting but Lyon could argue they would be unfairly hampered in their bid for qualification if a draw is awarded and that they could have played the fixture. A statement from the tournament organisers read: “As per its Covid-19 protocol, EPCR will convene match result resolution committees to determine the results of the cancelled matches and the decisions of the committees will be communicated as soon as practicable.” The outbreak could also have knock-on effects on Christmas fixtures. Exeter are hopeful their Premiership match at home to Gloucester can still go ahead on Boxing Day, with another round of testing set to take place next week. Glasgow are due to host the first of their annual fixtures against Edinburgh on 27 December. Premiership Rugby revealed its latest results on Wednesday, with 16 positive cases across Exeter and one other club. In September, Exeter’s director of rugby, Rob Baxter, called for an end to Covid testing for players on the grounds that “the actual transfer rates around players who are testing positive are so, so small”.