George North's knee injury is set to rule him out of Wales' autumn Tests against Australia, Georgia, New Zealand and South Africa.
Saracens score eight tries as they begin their quest for a third successive Champions Cup by thrashing Northampton at Franklin's Gardens.
Gloucester run in four second-half tries to earn a bonus-point win over Northampton Saints at Kingsholm.
Wales wing George North says he is hoping to bounce back from his 'nightmare' summer with the British and Irish Lions.
Audio & Video
Northampton Saints' Tom Collins tells BBC Look East about his family's sporting history ahead of the Champions Cup game with Saracens.
How to get into rugby union
How to get into rugby union - through the age groups up to the 15-player game or try rugby sevens, which made its Olympic debut in 2016.
Rugby alerts, newsletters and social media
Get latest scores and headlines sent straight to your phone, sign-up to our newsletter and learn where to find us on online.
Commentaries, clips and podcasts
Enjoy the best debate, analysis and interviews with BBC 5 live and World Service plus our rugby union commentary listings.
What's on BBC Sport this week
This week's sport on the BBC includes commentary of the European Rugby Champions Cup, Champions League football and the United States Grand Prix.