Twelve months on from the mind-numbing naivety which saw the future English champions bow out meekly from Europe with a vapid display at the Sportsground, Quins renew combat with the westerners needing just a point to qualify for the knock-out stages.
They shall certainly see and probably earn – if the weakened Connacht line-up is any indication – far more than that as they aim to make a definitive statement about their European ambitions by claiming one of those cherished top two seeds.
"We certainly haven't spoken about winning the competition," their Lions and England star Ugo Monye told the Irish Independent this week.
"We know that we've put ourselves in a good position. But we are also very much aware of the mistakes that we've made in the past. This tie last year, in fact, when two points would have got us through the pool stages against Connacht, but we couldn't get it.
"We slipped over the final hurdle and we don't want any repeats. As happy as we are with our current position, we need to keep our feet on the ground. We need to concentrate on our own processes.
"If we can control those things, then, hopefully, the results will keep coming. It's a huge opportunity for us to qualify this weekend and we don't want to let it slip."
The absence of Dan Parks, Connacht's influential out-half – albeit his performances had been robbed of their normal consistency in the past month – and the rampaging George Naoupu will handicap the visitors.
As the province prepared last night to welcome the incoming coach Pat Lam via a video link-up at a sponsors' event in London – a typically quirky conclusion to an unorthodox job search – Connacht could be forgiven for already having one eye on next season.
But Eric Elwood – hailed as a "hero" of Connacht by his erstwhile Lansdowne colleague O'Shea this week – will surely want to be remembered for something more than just the odd upset.
"We know their strengths and weaknesses, so it is very important for us to play rugby," said Elwood earlier this week. "You cannot kick foolishly or too much because they won't give the ball back to you. Collectively, they are very strong. I have just watched their last four games in the league and I think they are getting better. They are putting a lot of points on a lot of good teams and they are getting stronger, and they will be right up there when the cup is decided.
"After a couple of near losses, we are going there with a win under our belts, so it came at a good time heading to the English champions."
After a dispiriting festive period when they performed miserably in both inter-provincial derbies, Connacht at least returned to winning ways against the Dragons last weekend. But this is a fearsome prospect, particularly without two of their leading decision-makers.
Johnny O'Connor, who missed out on last weekend's clash, returns at open-side, while Eoin McKeon, who this week signed a two-year extended contract with the province, moves to No 8, replacing the injured Naoupu.
The 22-year-old came off the bench in the back-to-back fixtures against French side Biarritz. Miah Nikora, who returned to training last week following injury, is named on the bench along with replacement winger James Loxton, who could earn his first Heineken Cup appearance today.
Monye's return, to earn his 200th cap for the club he has played for since leaving school, is one of seven changes to the side that beat London Welsh and brought Quins to the summit of English rugby last week.
Mike Brown starts at full-back with Matt Hopper and Tom Casson returning to partner in the centres.
Harlequins – M Brown; T Williams, M Hopper, T Casson, U Monye; N Evans, D Care; J Marler, J Gray, J Johnston; O Kohn, G Robson; M Fa'asavalu, C Robshaw (capt), N Easter. Reps: R Buchanan, M Lambert, W Collier, C Matthews, T Guest, K Dickson, B Botica, G Lowe.
Connacht – R Henshaw; T O'Halloran, E Griffin, D McSharry, F Vainikolo; M Jarvis, K Marmion; D Buckley, J Harris-Wright, N White (capt); M Swift, M McCarthy; A Browne, J O'Connor, E McKeon. Reps: E Reynecke, B Wilkinson, R Loughney, M Kearney, E Grace, P O'Donohoe, M Nikora, J Loxton.
Ref – N Paterson (Scotland).
Harlequins v Connacht,
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