Worcester travel to Bucharest while Exeter host Pool Four leaders Dragons in the Amlin Challenge Cup on Sunday.
Worcester will be seeking a full house of points as they try to maintain the pressure on Pool One leaders Stade Franšais.
Bucharest v Worcester
Warriors will be looking to back up the bonus point victory over Banca Monte Crociati last time out with victory in Romania against a Wolves side that also enjoyed success over the Italians on home soil.
Head Coach Richard Hill retains the same back line the disposed of Crociati in difficult foggy conditions with Chris Pennell again captaining the side from full back.
Lock James Percival will play second row alongside Ben Gulliver while Sam Betty, Jake Abbott and Chris Jones occupy the back row.
The replacements see a welcome return to fitness for loosehead prop George Porter while Nile Dacres, called into the European squad this week, could also see senior European action for the first time.
"It will be cold, but I'm sure we will get a warm reception," admitted Forwards Coach Phil Davies.
"We have back-to-back games with Bucharest and it's vital to keep winning if we want to give ourselves a chance of progressing into the knockout stages of the Amlin Challenge Cup.
"Bucharest have already secured victory on home soil this season against Crociati and, at home in particular, they are a difficult team to face. They will be fired up in Romania to upset us.
Bucharest: 15 Florin Vlaicu, 14 Florin Ionita, 13 Jeff Makapelu, 12 Cristian Dinis, 11 Marian Apostol, 10 Ionut Florea, 9 Florin Surugiu, 8 Vasile Rus, 7 Adrian Ion, 6 Bogdan Petreanu, 5 Cristian Munteanu, 4 Cosmin Ratiu, 3 Vlad Badalicescu, 2 Florin Tasca, 1 Flavius Dobre.
Replacements: 16 Eugen Capatana, 17 Andrei Ursache, 18 Romulus Boar, 19 Valentin Popirlan, 20 Alexandru Mitu, 21 Vali Ivan, 22 Florin Fantanaru, 23 Ionut Niacsu.
Worcester: 15 Chris Pennell, 14 Tom Arscott, 13 Andy Short, 12 Sione Tu'ipulotu, 11 Josh Drauniniu, 10 Danny Gray, 9 Jonny Arr, 8 Chris Jones, 7 Jake Abbott, 6 Sam Betty, 5 Ben Gulliver, 4 James Percival, 3 Oliver Tomaszczyk, 2 Chris Fortey, 1 Bruce Douglas.
Replacements: 16 Ollie Hayes, 17 George Porter, 18 James Currie, 19 Aleki Lutui, 20 Nile Dacres, 21 Ollie Frost, 22 Andy Goode, 23 Errie Claassens.
Kick-off: 15:00 (14:00 GMT)
Venue: Arcul de Triumf
Referee: Alan Falzone (Italy)
Exeter v Dragons
With the Dragons undefeated in Pool Four so far this season following victories over Cavalieri Prato and Perpignan, the Chiefs know a victory is vital this weekend if they are to prevent the Welsh region from pulling further clear at the summit.
Although victorious last time out, the Chiefs have tinkered their starting XV slightly to give some of their frontline troops a well-earned rest from the heat of recent battles.
In the pack, Hoani Tui and Simon Alcott come into the front-row in place of Brett Sturgess and Neil Clark, whilst behind Chris Bentley is in for James Hanks and Ben White and James Phillips start in the back-row ahead of Tom Johnson and James Scaysbrook. In the sole change behind, former Dragons player Phil Dollman takes over from Jason Shoemark.
Meanwhile, Dragons have made eight changes to their starting line-up.
Welsh back row stars Danny Lydiate and Toby Faletau return to the starting XV in place of Lewis Evans and Tom Brown. Welsh hooker Lloyd Burns is also promoted from the bench in place of Steve Jones who drops out of the squad completely.
Ashley Smith has had to pull out of the team after picking up a hamstring injury in training and has been replaced by Andy Tuilagi who will make his first start for the Dragons. In Luke Charteris and Ashley Smith's absence Gavin Thomas takes on the captaincy role at Sandy Park.
In the backs, the blow of Tonderai Chavhanga's groin injury is offset by the return to fitness of Will Harries who comes straight into the starting line-up after recovering from ruptured knee ligaments. The other change in the backs is at scrum half where Joe Bedford comes in for Wayne Evans who takes his place on the bench.
Steffan Jones retains the fly half jersey for the trip to Devon and Tom Riley continues as centre partner of captain Ashley Smith after scoring a try in his 50th Dragons cap during last week's 14-14 draw against Glasgow Warriors.
The other two changes come in the pack. Phil Price starts in place of Nathan Williams and Rob Sidoli comes in for Scott Morgan as the Dragons continue their rotations of the front five.
Exeter: 15 Luke Arscott, 14 Gonzalo Camacho, 13 Nick Sestaret, 12 Phil Dollman, 11 Matt Jess, 10 Ignacio Mieres, 9 Haydn Thomas, 8 James Phillips, 7 Ben White, 6 Richard Baxter, 5 Chris Bentley, 4 Tom Hayes, 3 Craig Mitchell, 2 Simon Alcott, 1 Hoani Tui.
Replacements: 16 Neil Clark, 17 Chris Budgen, 18 John Andress, 19 Alastair Muldowney, 20 Dave Ewers, 21 Patrick Phibbs, 22 Gareth Steenson, 23 Joseph Tatupu.
Dragons: 15 Martyn Thomas, 14 Will Harries, 13 Tom Riley, 12 Andy Tuilagi, 11 Adam Hughes, 10 Steffan Jones, 9 Joe Bedford, 8 Toby Faletau, 7 Gavin Thomas, 6 Dan Lydiate, 5 Robert Sidoli, 4 Adam Jones, 3 Nathan Buck, 2 Lloyd Burns, 1 Phil Price.
Replacements: 16 Rhys Buckley, 17 Nathan Williams, 18 Keiron Jenkins, 19 Scott Morgan, 20 Lewis Evans, 21 Wayne Evans, 22 Aled Brew, 23 Jason Tovey.
Venue: Sandy Park
Referee: Carlo Damasco (Italy)