Wednesday 12 October 2016 08:59, UK
Defending champions Saracens begin their title defence against three-time champions Toulon while Sale and Scarlets will be out to prove they're not just there to make up the numbers.
The double winners returned to the top of the Premiership with victory over Wasps on Sunday and that puts them in good stead ahead of Saturday's trip to the Stade Felix Mayol.
Jonathan Davies' return to Parc y Scarlets, along with the signing of Super Rugby star Johnny McNicholl, have bolstered the Welsh region's backline, but Sale have shown they can mix it with the best in the Premiership when they're in the mood.
Champions Cup record: P73 W49 D0 L24
Best finish: Winners (2015-16)
What's hot: Defending champions both in Europe and in the Premiership, Saracens are the team to beat in every competition. They have made a good start to the defence of their Premiership title, with a defeat to Harlequins at the Stoop the sole negative of their domestic season.
What's not: The departure of former captain Alistair Hargreaves, who last week announced he has been forced to retire from the game on doctor's orders following a concussion injury.
What's changed: With the departure of Charlie Hodgson, Alex Lozowski was brought in as an understudy to Owen Farell. However, with Farrell's ongoing back problems, Lozowski has been given the No 10 jersey and has done a superb job of pulling the strings. The youngster was rewarded for his composure with a call-up to Eddie Jones' England training squad.
One to watch: Schalk Burger has been brought in to fill the void of recently-retired tackle enthusiast Jacques Burger, and the South African has already made a literal and figurative impact at the club. The Springbok will add value to Saracens' already burgeoning pack throughout their campaign.
Champions Cup record: P41 W33 D0 L8
Best finish: Winners (2012-13, 2013-14, 2014-15)
What's hot: Francois Trinh-Duc's arrival has forced Toulon to adjust their style of play but Mike Ford could be the man to get their backline firing. It would be foolish to write off a side that includes a plethora of stars such as Samu Manoa, Duane Vermuelen and Leigh Halfpenny.
What's not: Toulon are sorely missing Matt Giteau, both on and off the field. They are in rebuild mode after losing the likes of Bakkies Botha, Carl Hayman and the Armitage brothers - people who knew what the club was about - and the pressure placed on the squad by their mad owner, Mourad Boudjellal, doesn't help matters.
What's changed: There were plenty of comings and goings during the off-season as the Toulon rebuild begins. Liam Gill arrives from Super Rugby with South Africa forwards Juandre Kruger and Marcel van der Merwe also moving to the Stade Mayol.
One to watch: Georgia international Mamuka Gorgodze has been immense for Toulon this season.
Champions Cup record: P129 W60 D2 L67
Best finish: Semi-finals (1999-2000, 2006-07)
What's hot: The arrival of a host of star names to the club; the Welsh region has spent heavily during the off season in a bid for silverware.
What's not: Scarlets' strength on paper is not being replicated on the pitch; they lost their first three PRO12 games this season. They have since snapped out of the losing streak by beating Connacht, Treviso and the Dragons in succession but have only played in fits and bursts.
What's changed: Lions centre Jonathan Davies has joined brother James in the squad, while Springbok prop Werner Kruger and Johnny McNicholl of the Crusaders have also been brought into the fold.
One to watch: Johnny McNicholl has been carving up defences in Super Rugby for some time and will be eager to start life at his new home with similar antics.
Champions Cup record: P49 W18 D0 L31
Best finish: Quarter-finals (2005-06)
What's hot: Josh Beaumont's stock in English rugby is rising and with the task of leading a relatively inexperienced squad causing no apparent burden to the No 8, his contribution to the Sharks cause will be vital. Beaumont was recently part of Eddie Jones' training squad so they 24-year-old is learning his trade at the top.
What's not: Injuries to key players. Rob Webber broke his arm on debut for the Sharks last month, while scrum-half Peter Stringer recently suffered the same injury to add to their woes. Sale do not have the kind of depth that other clubs can rely on and will be hoping the injuries don't derail their season early on.
What's changed: The loss of Danny Cipriani to Wasps is a big hole for Sale to fill but the arrival of AJ MacGinty from Connacht goes a long way to plugging that gap. Another big signing is that of Mike Phillips from Racing 92, who will have to step up in the absence of Stringer.
One to watch: Josh Charnley is the latest rugby league player to cross the divide to try his hand at union. The Wigan winger recently starred for the Warriors in the Super League Grand Final and has promised more of the same pace and finishing at his new club.
