Saracens, Northampton, Gloucester, Glasgow and Ulster will duel it out for the three remaining Champions Cup quarter-final spots this weekend.

Exeter, Leinster and French trio Racing 92, Toulouse and Clermont Auvergne are already into the last eight.

However, none are yet assured of the home advantage that has often proved crucial in the knock-out stages.

Premiership sides Sale, Harlequins and Bath, along with Welsh side Ospreys, are already out of contention.

How it works

The five pool winners and the three best runners-up will make up the quarter-finalists.

The pool standings are initially decided on points - four for a win, with bonus points on offer for scoring four tries, and also for keeping a losing margin down to seven points or less.

If teams are level on points, the tie is broken by whichever has got more points from their head-to-head meetings, followed by the aggregate score and most tries in those same two matches.

If two teams from different pools finish level on the same points in the race for a runners-up spot or a quarter-final seeding, points difference and tries scored are the tie-breakers.

The four highest-ranked teams from the pool stages will be at home in the last eight. The two highest-ranked teams will also play the semi-finals at home if they progress that far.

The current standings

Which, as it stands, would translate to a quarter-final line-up of:

Leinster v Gloucester

Toulouse v Clermont

Exeter v Ulster

Racing 92 v Saracens

But there is still plenty to play for...

Five into three won't go

With three spots open to the best placed runners-up, here are the respective records of the second-placed teams in more detail.

Ulster should be fine. They play Bath, bottom of Pool Three with five defeats in five games, at home in their final game, knowing that even a draw is likely to be sufficient, given their vastly superior points difference to Northampton.

Saracens host free-running, fast-scoring Pool Four leaders Racing 92 in their final pool-stage game. The defending champions lost 30-10 in the reverse fixture in the French capital in November. A bonus-point victory would all but guarantee their place given their healthy points difference. A win would probably be enough. Anything less and they are in danger.

Gloucester have a tricky trip to Toulouse, who lead Pool Five with a 100% record, to negotiate. However, their points difference, considerably better than both Northampton and Glasgow, may prove telling.

Northampton also head to France. Opponents Lyon seem to have prioritised their domestic Top 14, where they are second, ahead of Champions Cup, in which they have won only one of five matches. Northampton won 25-14 when the teams met at Franklin's Gardens in November. A repeat would put pressure on Saracens and Gloucester who may have harder encounters given their opponents will be chasing home quarter-finals.

Glasgow are an outside bet. However, a bonus-point victory away to Sale, who are bottom of Pool Two, combined with two of Saracens, Gloucester and Northampton failing to win would take them through.

Munster, third on 11 points in Pool Four, have an even slimmer chance. They need Racing 92 to beat Saracens, and Glasgow, Northampton and Gloucester all to fail to win, plus a bonus-point win of their own at home to Ospreys.

Home advantage

Leinster travel to Pool One bottom side Benetton Treviso knowing a victory of any sorts will confirm them as the quarter-finals' top seeds.

Exeter will guarantee a home quarter-final with a home victory over La Rochelle, and will book themselves in for a potential semi-final at Sandy Park if they better both Racing 92 and Toulouse's results.

Ulster could sneak into the top four seeds, but require Clermont to lose at home to Harlequins to clear the route to the top of Pool Three and a huge points swing in their favour via a home win over Bath and heavy defeats for one of Racing 92, Exeter or Toulouse.