Gloucester v Munster, Kingsholm Stadium, 7.45pm, Pool 2
Live radio commentary on Game On, RTÉ 2fm from 7pm, also live on BT Sport 2
Leinster v Toulouse, RDS, 1pm, Pool 1
Live TV coverage on BT Sport 2, Channel 4, Virgin Media One
Ulster v Racing 92, Kingspan Stadium, 3.15pm, Pool 4
Live TV coverage on BT Sport 2
For Gloucester it's simple: win or go home, or else go to Castres in the final round with nothing to play for.
So tight is the pool that Munster, on the other hand, can afford to lose and still be in with a shout of making the knock-out stages.
The two-time champs are favourites to win this one but the hosts are hurting from two Premiership losses in a row and Johan Ackermann wants to make a statement about where his side really are at.
There will be a full house and the Shed will provide a warm welcome for Peter O'Mahony and his men.
This pool is unlikely to produce two qualifiers so the result of the Exeter-Castres game will determine a lot going into the final round when the English Premiership leaders come to Thomond.
Two wins in the final two games will secure top spot for the champions but the second placed side in this pool should also progress.
However, if the French outfit manage to do the double over Leinster then the whole dynamic of the holder's season changes.
From going unbeaten last year to losing twice in the pool would give hope to whoever they get in an away quarter-final, providing they take care of business away to Wasps next week.
That said, Leinster were an intercept away from a win in France and should have enough muscle memory to get past the team currently second in the Top 14.
The loss of Johnny Sexton through injury cannot be understated - he's the World Player of the Year for a reason - but there are plenty of leaders in Leo Cullen's team and not fronting up here would be unforgivable.
Ulster last qualified for the knockout stages in 2014 and are enjoying their best run of form in some time.
Ahead of where many thought the squad, with a new coach and a raft of new players, might be at this stage, they will fancy themselves to get a result.
Last year's beaten finalists, however, won't go down easy. They are the best of all the teams in this season's competition with 19 points already to their name.
Top spot might just be out of reach for Dan McFarland's team (Racing host Scarlets the following week) but even a bonus point would keep Ulster very interested travelling to Leicester in the last round.
Follow Gloucester v Munster (KO 7.45pm) via the live blog on RTÉ.ie/Sport and the News Now App, or listen live on RTÉ 2fm's Game On, with commentary from Michael Corcoran and Donal Lenihan.