The likely prize is a last-eight clash against powerful French outfit Clermont Auvergne, formerly Montferrand, next month, but Gold accepts Irish have got it all to do.

“Contrary to popular belief, we are not happy with being six points down. We are disappointed to be behind for the second leg,” he said.

“Now, we have a tough hill to climb, because they apparently rested some key players who will be back on Sunday, and we also expect them to be a handful in the scrums this time after we dominated that area in the first leg.”

Gold has made six changes, three behind the scrum, where centre Rodd Penney makes his first-team debut and former England back Mike Catt is poised to return at fly-half, provided he recovers in time from a calf muscle injury.

Up-front, there are starts for prop Pierre Durant and lock Nick Kennedy, but the Irish injury list includes wing Scott Staniforth (shin splints), full-back Michael Horak (hamstring), prop Neal Hatley (hand) and flanker Kieron Dawson (knee).

Clermont Auvergne, Irish’s probable quarter-final opponents, take a 29-point lead with them to the Borders on Sunday, but Saracens are nowhere near as comfortable in their attempt to overcome Italian side Overmach Parma.

Saracens lost the first leg 19-18 last weekend on a pitch described by coach Rod Kafer as one of the worst he had seen.

But if the Zurich Premiership outfit prevail in the Vicarage Road return, they can look forward to new year home and away meetings with 1997 Heineken Cup winners Brive, who lead Cetransa El Salvador 57-6 after the first leg.

The European Shield competition, for Challenge Cup first-round losers, will inevitably see English pair Leeds and Worcester progress.

Leeds smashed Spanish amateurs Valladolid 121-0 at Headingley last weekend, while Worcester saw off Rovigo 48-3 in Italy, making this weekend’s return encounters a formality.