That is because it has been decided that the 2020 Heineken Champions Cup and Challenge Cup finals will be played at new venues after tournament organisers decided to move the games away from Marseille.
The French city will now stage the 2021 finals, with Tottenham Hotspur Stadium in London hosting in 2022.
Saints are set to face Exeter Chiefs in the Champions Cup quarter-finals on the weekend of September 19.
"Due to the many uncertainties created by the Covid-19 pandemic, it has been decided that the 2020 Heineken Champions Cup and Challenge Cup finals will not now be held in Marseille as planned and the matches will be played at a new venue or venues," said a statement from European Professional Club Rugby.
"With tens of thousands of fans scheduled to travel to the south of France, the board of EPCR and the local organising committee have agreed that insufficient safeguards are currently in place during the public health crisis to stage two high-profile matches at the 67,000-capacity Stade Velodrome.
"As a consequence, EPCR is currently working with its shareholder leagues and unions to secure an alternative venue or venues for the two finals which will be played on the weekend of October 16/17/18, and details will be announced as soon as practicable.
"Tickets for this season's finals will be valid for the 2021 weekend with no change to category or seating, and all ticket holders will be contacted by email within the next 48 hours with details of how to avail of a full refund if required."
EPCR announced in June they still plan to stage the 2020 finals in mid-October, despite the coronavirus pandemic.
The quarter-finals of both tournaments will be played on the weekend of September 18-20, with the semi-finals scheduled for September 25-27.
EPCR added: "As is now customary during the pandemic, the matches will be subject to government guidelines with the health and welfare of players, club staff, match officials, supporters and the wider rugby community to the fore."