At this point, the management are hopeful that the experienced Ireland international will be fit for selection for the Ulster game.
Eoin O'Malley, having returned from a six-week break due to a calf injury, underwent a scan on his knee on Sunday afternoon.
Unfortunately the scan results revealed that he has ligament damage and he will be unavailable for both of the upcoming finals.
Cian Healy (ankle and cramp) was withdrawn during the semi-final at the RDS as a precaution but the Ireland prop is expected to fully recover.
The province's medical team are confident that full-back Rob Kearney (back) will be available for selection, while the outlook for Brian O'Driscoll (knee) is looking more positive.
A final decision regarding their selection will be made on Thursday evening ahead of the team announcement on Friday.
O'Driscoll lies one try behind Vincent Clerc's Heineken Cup try-scoring record of 32, while his long-time centre partner D'Arcy is just one game shy of becoming the joint fifth most-capped player in European rugby.
Jonathan Sexton, meanwhile, has scored 88 points so far in this season's Heineken Cup campaign.
Officially, Leinster will have an allocation of 7,500 supporters travelling over to London but it is expected that tens of thousands will make the trip to Twickenham for next Saturday's all-Irish decider.
With that in mind, the Official Leinster Supporters Club - in association with Bank of Ireland - have published an away guide featuring relevant and important travel information which can be downloaded from www.leinsterrugby.ie this week.
Bank of Ireland branches in the Leinster area will turn blue in the lead up to the game with flags, posters, balloons and bunting, while ATMs will carry a Leinster Rugby message.