Sale Sharks boss Steve Diamond says European competition provides an added stress to an intensive Premiership season.
Premiership champions Exeter will begin their title defence at Gloucester when the 2017-18 season starts on 1 September.
Sale boss Steve Diamond says they were justified in signing Denny Solomona but Castleford believe the legal saga could happen again.
Australia utility back James O'Connor signs for Premiership side Sale Sharks from Toulon on a three-year contract.
Audio & Video
Sale Sharks’ former Wales scrum-half Mike Phillips says the time is right to retire as he looks forward to the final game of his career.
How to get into rugby union
How to get into rugby union - into the thick of 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 the World Aquatic Championships, England v South Africa in the third Test and the Challenge Cup semi-finals.