If Ulster want to make the last eight in Europe as group winners then nothing else but a victory will do against Glasgow Warriors on Friday night at Ravenhill (kick-off 8pm).
The sell-out clash has Pool Four leaders Ulster looking to get back on track in the group after a loss - their first of the season - to Northampton Saints last month and pursue their target of topping the group and securing a home quarter-final draw as one of the top four seeds in the last eight.
Ulster head the group by three points from Castres who face the Saints in Franklin Gardens tonight.
The English side are a further two points behind, but still hold high hopes they can win their two remaining games and qualify as a best runner-up or even nip in ahead of the other two challengers and win the group.
From Ulster’s point of view a straight forward win keeps them in the driving seat, but if they were to take a try scoring bonus point (score four tries) and Northampton were to beat Castres, with neither side taking a try or losing bonus point then the Irish Province would have won the group before next week’s trip to France.
It would mean Ulster would be looking to win in France for the first time in European history to at least leave themselves in with a shout of being one of the top four teams in the last eight and securing that valuable home draw in the quarter-fianls.
Results in the other pools over the next week also have a bearing on what the final outcomes may be.
The various permutations were not lost on Ulster head coach Mark Anscombe’s this week.
“We have to win against Glasgow first and foremost,” he said.
“We have to make sure we prepare for the challenge that lies ahead. This week it is Glasgow and that is all we are concerning ourselves with.
“We lost our last game in the competition at home and we must ensure we bounce back from that.
“Yes, it is great to be in the position we are and yes it is great that we are able to control what happens in our group.
“But we are also not good enouigh yet to get ahead of ourselves about where we are.
“It is very much about understanding who we are playing this week, where we have to play, how we have to play and going about our jobs.”
Anscombe made five changes to the side which defeated Scarlets last week in the PRO12 with Jared Payne being the big news boost and able to start at fullback.
Rory Best and Iain Henderson, both rested last weekend, return to the pack - Henderson replacing the injured Dan Tuohy.
Tuohy limped off at Ravenhill last week with a recurrence of a calf strain and he may miss next week’s game in Castres as well.
John Afoa also starts ahead of Adam Macklin, who has no place in the side this week as Declan Fitzpatrick returns from injury and takes the tighthead replacement spot on the bench.
Paddy Wallace is the only other change in the backline, coming in for the injured Luke Marshall.
Marshall underwent surgery on Wednesday on a broken finger and could be out for up to three weeks.
However he was still expected to be available for Ireland if called up ahead of the Six Nations.
Paul Marshall is named on the bench ahead of Michael Heaney and Chris Cochrane and Michael Allen are also included on the replacements.