Silverware the driving force for O'Shea and Jackman
The Irish may have exited Europe already, but the flag still flies in the coaching booths. Of the eight teams left in this year's four semi-finals, three are coached by men who once wore the green, while there are former Ireland internationals on the staff of two others.
Tonight, Conor O'Shea welcomes Bernard Jackman's Grenoble to Harlequins' Stoop. They do battle for the secondary prize, but regardless of the tournament's stature this game is of equal importance for both men.
O'Shea is hoping to sign off in London with a parting gift, a fourth trophy in six years that would cap a successful stint in the city before he moves to Italy. Jackman, meanwhile, is on a mission to deliver the first silverware of his time in charge of a club still establishing themselves as Top 14 regulars.
Winning the Challenge Cup ensures Champions Cup qualification for next season and Grenoble's defeat to Castres last weekend suggests this is their best route to the top table. At seventh in the Premiership, Quins could also do with the safety net of a guaranteed place.
With Jake White's Montpellier likely to come out on the other side of the draw, there are no guarantees of silverware, but O'Shea is looking forward to welcoming Grenoble's Irish contingent despite welcoming Mike Prendergast to Surrey last season for a few days.
"I can't wait to play them," he said. "I know Clermont and Toulouse and they play brilliant rugby but Grenoble are playing a style that is completely different to a lot of teams in terms of the pace. Every French team can play with pace but they don't like it both ways. Grenoble just want to get into a game … it will probably suit us as well and it will be a great game of rugby."
However the final weeks of O'Shea's time at Harlequins go, the former Ireland full-back will be remembered fondly after restoring the club's reputation in the years that followed the 'Blood-gate' scandal and leading them to the 2011/'12 Premiership title. Jackman, meanwhile, is trying to leave his own legacy at a club that has only fleetingly come close to success in the past, as well as some practical benefits that a cup run can bring.
"Everyone talks about the 'Mammouths', the great team in Grenoble's history that lost the Top 14 final to Castres about 22 or 23 years ago (1992/'93) and for me it's important that whenever I leave here or the players leave here that the city talks about this team," he said.
"We won't be the 'Mammouths' because the 'Mammouths' were mountain men, who were a massive, aggressive pack. We're not that type of team. But we can create our own identity. We want to create our own legacy and push this club up as high as we can, and there's nothing like a Cup run to galvanise the support.
"We're down on crowds. All of France is down, but financially we're not where we need to be in terms of revenue. In France, you have to balance the books so there was a bit of pressure on us to win. A semi-final gets you gate receipts.
"We don't have a benefactor, so the only thing that can solve our revenue problems is results and a Cup run, and to play the final in Lyon - the whole city would be gone.
"That event builds a fan base. You can do all the mad things you want but what really puts bums on seats is a team that fans respect and love. That's what we have to do.
"It's not easy, but the will is there, and with a good strategy we'll get there."
The duo are at different stages of their careers and their routes back into Irish rugby are far from guaranteed or clear. Their focus is on tonight and on the legacy they will leave at their current clubs.
HARLEQUINS - M Brown; M Yarde, G Lowe, J Roberts, T Visser; B Botica, D Care (capt); J Marler, J Gray, A Jones; J Horwill, S Twomey; C Robshaw, L Wallace, N Easter.
Reps: D Ward, M Lambert, K Sinckler, C Matthews, J Clifford, K Dickson, N Evans, R Chisholm.
GRENOBLE - G Aplon; X Mignot, C Farrell, N Hunt, L Dupont; J Wisniewski, C McLeod; S Taumalolo, A Heguy, D Edwards; B Hand (capt), J Percival; M Diaby, F Alexandre, S Setephano. Reps: L Jammes, F Barcella, W Desmaison, M Marie, H Vanderglas, J Hart, F Gengenbacher, F Estabenez.
Ref - J Lacey (Ireland)
Harlequins v Grenoble,
Live, BT Sport Europe, 7.45