Edinburgh head coach Alan Solomons admits Saturday's Heineken Cup clash with Perpignan is a must-win encounter if the capital club are to rescue their European ambitions.
The Murrayfield side sit third in Pool 6, five points adrift of leaders Munster with two games to play.
But with only the six group winners and two best-placed runners-up offered slots in the knock-out stages - and three other second-placed sides dropping into the Amlin Challenge Cup - Solomons knows his side cannot afford any more slip ups.
However, s tanding in their way at Murrayfield are Perpignan, who overturned Edinburgh's half-time lead to inflict a painful 31-14 defeat at the Stade Aime Giral in October.
"If we want to continue in Europe then we need to win this game", Solomons said.
"There is no doubt that Perpignan are a good side. They are very powerful and have great strength in depth like most Top 14 teams.
"It will be big challenge for us, there is no question about that. They are a good team with lethal strike power.
"We need to make sure that we do not create opportunities for them, which means cutting our error rate and maintaining our discipline in our systems."
Last week's postponed New Year's Day clash with Glasgow has at least allowed Edinburgh's players to rest up ahead of Perpignan's visit.
The derby call-off has resulted in a 10-day turnaround for the Murrayfield men and Solomons believes that, on balance, the rest has served his squad well, despite the disruption to regular rugby.
He said: "It meant that we haven't had continuity in playing and lost a bit of rhythm but, on the up side, a lot of the players needed a rest and I think it will stand us in good stead.
"The players have looked refreshed in training and I think it was beneficial for them, physically and mentally."
Solomons has made one change to the side that was set to start on New Year's Day, with lock Izak van der Westhuizen back in the front line after his return from a groin injury.
The club also welcome the return of centre Matt Scott, who starts on the bench, having recovered from the hand injury he suffered playing for Scotland against Japan in November.