COACH Eric Elwood cannot even count on the element of surprise as these two have met three times in little over a year, Connacht losing out 30-22 at The Sportsground in round two.
Conor O'Shea's Harlequins, currently in control of the Premiership, are one of three clubs with a 100pc record in the competition. That is not likely to change tomorrow.
Quins are 10 points clear of Biarritz, have scored more points (180) and more tries (21) than any other club in Europe and are on course for a first-seed finish.
This is tempered somewhat by the low quality of the pool, populated by a disinterested French club, an ill-equipped Connacht and the Italians Zebre, who are simply out of their league.
It is understandable why other coaches have voiced their concerns at the inequities of the pool phase. That won't bother Chris Robshaw et al.
Harlequins v Connacht
TOMORROW, SKY SPORTS 1, KO 1.35