Kicking off the round is Zebre v Ospreys on Thursday - effectively a must-win encounter for the Welsh outfit if they are to make the RaboDirect PRO12 play-offs.
A loss for the visitors Ospreys, without picking up any league points would take away their mathematical chances of making the play-offs, whereas a five-point win would put the pressure on Ulster, bringing them level on points.
On Friday meanwhile, a bonus point win for Ulster at Ravenhill against leaders Leinster would seal their top-four spot, regardless of the Ospreys result 24 hours earlier.
Maximum points for Leinster would gain them home advantage having already qualified for a top four finish.
Also on Friday, the Scarlets have the chance to secure European rugby next season needing just two points from their game with Newport Gwent Dragons to deny Cardiff Blues or Edinburgh any mathematical chance of beating them to sixth place.
Glasgow Warriors' bonus point victory over Edinburgh in their rearranged fixture last weekend lifted the Warriors into second spot, while they have racked up the most wins, 16, in the competition so far this season.
Five points for them away to Treviso will edge them closer to a top-two spot and, depending on how Munster and Ulster fare, could guarantee it.
Treviso meanwhile, are locked in a battle with Zebre for the Italian berth in the European Rugby Champions Cup.
Munster take on Edinburgh on Saturday and by then the picture will be far clearer for the Irish province, who will look for victory to set them up for their final regular season fixture against Ulster.
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