ESPN's rugby predictions: Games of the week, potential upsets & more

As the Aviva Premiership and Top 14 regular seasons draw to a close, and the PRO14 playoffs begin, there is plenty to play for across Europe's big leagues.

But whether your club is fighting for the title, or to avoid relegation, ESPN takes a look at who is set for a memorable weekend and who, quite frankly, is not.

Player to watch

Premiership (Martyn Thomas): Jack Willis (Wasps). The back row has been one of the breakthrough players of the season so far. He picked the perfect time to put in a standout performance last weekend, as his work at the breakdown helped Wasps beat Northampton in front of the watching Eddie Jones. Such displays have led to suggestions that Willis could tour South Africa with England, but talk of a Test call up must wait for now. Willis and Wasps travel to Newcastle to face fellow semifinalists Falcons this weekend, looking to sign off from the regular season in style.

PRO14 (Cillian O Conchuir): Simon Zebo (Munster). In his final season at Munster before departing to team up with Teddy Thomas and co at Racing 92, Zebo hasn't made much of an impact. Saturday is the fullback's farewell to Thomond Park and for all his quality, one PRO14 title is all he has to show for his time in red. Munster and Zebo have a chance to save their season against Edinburgh on Saturday and defeat is not an option for Johann van Graan or his players.

Top 14 (James Harrington): Aurelien Rougerie (Clermont). He's not the only French rugby legend retiring this weekend -- Vincent Clerc is also expected to hang up his boots on Saturday, even though Toulon booked their place in the playoffs with that win over Castres last weekend; while Freddie Michalak's career could also end this weekend. But RoRo, who has been with Clermont since he was eight, is the definition of a one-club legend. On Saturday, after 19 years as a professional, he will play his 418th and final game for the club, his 498th including international appearances. He has scored 134 tries, 96 of them in the Top 14, putting him third behind fellow retiree Clerc and Laurent Arbo, who both have 100. His 24th match against Toulouse, at the imposing Stade Marcel Michelin, is going to be emotional. Expect an earthquake if he scores.

Game of the weekend

Prem: Sale vs. Leicester, Saturday, 4 p.m

At the beginning of the month it looked as though a top-six finish was the least the Tigers could expect from a season that had started in disappointing fashion. But back-to-back home defeats halted their playoff push and heading into the final day of the regular season, left them in serious danger of missing out on Champions Cup qualification altogether. Sale host Leicester in seventh and with designs on the top six. The Sharks must beat the Tigers to have any hope of realising that aim, while a bonus-point win would likely secure it with Gloucester at Saracens. With two more wins than the Sharks, Leicester need a bonus point to be sure.

PRO14: Scarlets vs. Cheetahs 6.35 p.m.

Scarlets complained last week that Dragons had tried to drag them down to playing on their level of average. Not so this week as the two of the most attack-minded teams in the PRO14 go head-to-head in Wales. The Cheetahs have almost justified the inclusion of South African teams in the competition with their style of play, but while their running rugby can sometimes be breathtaking, their inability to defend is worrisome. And as Leinster showed in the Champions Cup semifinal, Scarlets can be picked apart. Let the fireworks begin.

Top 14: Pau vs. Toulon, Saturday, 8 p.m.

Three matches could easily make this slot -- Castres vs. Oyonnax and La Rochelle vs. Stade Francais pit playoff hopefuls against relegation rivals. All three should be tension-filled epics with tactics along the lines of attack, attack, attack -- then attack again. But Stade du Hameau hosts the game to rule them all. Pau, in eighth and two points off the playoffs need a big win to sneak into the all-important top six. For Toulon, two points off second, a big win could take them straight to the semifinals without having to contest the playoff qualifiers. Two sides. Everything to play for; (almost) everything to lose. What's not to like?

Potential upset

Prem: Northampton vs. Worcester, Saturday, 4 p.m.

An upset in all but name, perhaps, but Saints would expect to beat the Warriors at home nine times out of 10. Unfortunately for the hosts that one occasion could well be Saturday. Northampton will want to end a disastrous season on a high, and give the departing Ben Foden a fitting send-off but with two wins in their last three league games, Worcester arrive at Franklin's Gardens in form. The visitors have a top 10 finish in their sights and will be determined not to let Northampton -- or sentiment -- stand in their way.

PRO14: Munster vs. Edinburgh, Saturday 3.15 p.m.

It has been a brilliant first season for Richard Cockerill in Scotland and Saturday's clash with Munster provides a chance of proving that they are back among the PRO14 elite by no fluke. They have lost their last two games at Thomond Park, but in a one-off game, with Munster looking far from their best, Edinburgh will fancy their chances. Don't expect a very expansive game -- it could come down to whoever has the best kickers. Sam Hidalgo-Clyne has announced he will leave for Scarlets, and if it came down a battle of nerves between the him and Ian Keatley, you would put money on the Scottish scrum-half.

Top 14: Racing 92 vs. Agen, Saturday, 8 p.m.

Blame Beyonce and Jay-Z. Racing have not lost at home since they moved into the indoor U Arena in December. But their air-conditioned, plastic-pitched fortress is out of bounds for at least a month so the King and Queen of hip-hop can rehearse for their world tour. It means Racing's final 'home' match of the year is in Vannes, Brittany, more than 450 kilometres away. A similar distance did not bother the Franciliens when they played Munster in Bordeaux in the Champions Cup semifinal, but if they lose this weekend, and either Toulouse or Toulon win, they will drop out of second place, lose the bye to the semifinals that comes with it -- and have to find a stadium for the 'home' playoff qualifier they will suddenly have to play. And it will all be Beyonce and Jay-Z's fault...

Big weekend for

Prem: Harlequins. Exeter are the visitors as John Kingston oversees his final game in charge, and Premiership top seeds Chiefs have the opportunity to condemn their hosts to an 11th-placed finish. It would be a sad way to bow out for a man who has given 17 years of his life to the club. A change has been needed at the top for some time, but the first-team squad has attempted to inject some fun into training this week and they have the opportunity to put a modicum of pride back into a season that has flatlined in 2018. The club has grand plans for the future -- a 30,000-seat stadium included -- and finishing second-bottom is not good enough.

PRO14: Joey Carbery. The biggest story in Irish rugby at the moment is whether Joe Schmidt, who met Carbery last weekend, can convince the Leinster prodigy to join Ulster. While Ulster insisted that neither he nor Ross Byrne had an interest in joining Dan McFarland's new team, former players like Brian O'Driscoll have weighed in on the matter, stating that he should move north. The biggest question is whether Ulster can match his ambition or provide the coaching set up he learned under at Leinster.

Top 14: Christophe Urios, Frederic Charrier and Joe El-Abd -- The Castres coaching team. Victory over Oyonnax would guarantee Castres a playoff place, and Champions Cup rugby next season. Thing is, the coaches arrived from Oyonnax at the start of the 2015-16 season having guided that club to a top six finish, and a win for their current employers on Saturday condemns their former club to a survival playoff. This is professional sport. This is what can happen. But the Castres coaches would need hearts of graphene not to feel a tug at the heartstrings after all they did at their former club.