Irish can still finish level on points with Stade at the top of Pool 5 but they can't make it to the knockout stages because a last-gasp bonus-point try from Antoine Burban in the French capital in Round 4 meant Stade picked up more match points across their head-to-head games.
It would be a surprise if Irish don't claim a fourth bonus-point win and a fifth victory overall in Italy despite the fact that the motivation of a quarter-final spot has now been taken away from them. Brian Smith's side won the reverse fixture 60-11 at the Madejski Stadium in October, scoring nine tries in the process. They head into this game on the back of successive wins as well after they beat Worcester Warriors to ease their relegation fears in the Aviva Premiership before putting 13 tries past Lusitanos in a 79-3 success last weekend.
I Cavalieri Prato won't roll over at the Stadio Enrico Chersoni, though, with the hosts having come agonizingly close to stunning Stade at the same venue in Round 2. They were only undone by a late try three months ago despite having a man sent off in the first half and they have since recorded back-to-back victories over Lusitanos. They almost threw Irish a lifeline last week when they kept Stade to three tries until the 78th minute in France and they will be going all out to gain a major reward for a string of impressive performances this term.
London Irish missed just two tackles in their 60-11 defeat of Prato in Round 1.
London Irish have scored more tries (34) and points (244) than any other side in the competition this season.
Cavalieri Prato have won three of 23 games in their Amlin Challenge Cup history, two of which have come in their last three games (against Lusitanos XV).
Irish have won all 11 of their games in the Amlin Challenge Cup against Italian opposition, averaging 48 points per game.