Joe Schmidt has said that Leinster will need a miracle if they are to make to quarter-final stage of the Heineken Cup.
The holders of the Cup have two wins from four games, and sit second in Pool 5, just one point ahead of Exeter.
The Leinster coach told Sky Sports News: "Miracles happen in sport, I guess, but mathematical long shots very seldom come into being.
"I don't think we have the same depth as some of the big-spending French clubs. It's hard to take defeat two weeks in a row, with the amount of effort the players put in.
"The other challenge for champions is they always look pretty good when they are on top. It is how they come back from adversity that is the real challenge."
Leinster will have to rely on other results to ensure that they make the knockout stages.