Constable sustained a shoulder muscle injury in the defeat to Gwent Dragons last week and is replaced in the side by Shane Stewart.
Paddy Wallace, originally excluded from the panel, now moves up to take his place on the bench.
“Shane will offer something completely different from Ryan,” said coach Alan Solomons, who will have Kiwi hooker Matt Sexton back to fitness again after a doubt concerning a hamstring problem.
“It’s a pity about Ryan, he has been excellent this season, and he has formed a very useful midfield combination with Paul Steinmetz. But Shane will not let us down. He’s solid in defence and a very strong runner.
“But no matter about running the ball in the backs, we need primary possession first and foremost. We have worked quite a lot this week on our set-pieces and hopefully that will eliminate the errors.”
Following the big win against Leicester in Paris, Stade Francais are highly fancied to make it two victories on the trot and take pole position in Pool 1. However, they have come to Ravenhill twice before as the highly-rated favourites and each time left with their tails trailing behind them.
Gary Longwell, who will be playing his 42nd game in Europe, and along with Andy Ward and David Humphreys are the only remaining players from the 1999 success. LongwellHe, believes that the full-house at Ravenhill will lift Ulster once again.
“French teams are sometimes inclined to get very nervy in front of a very partisan home crowd,” he said. said Longwell who will be earning his 123rd cap.
“Playing at Ravenhill is usually worth six or nine points with the crowd behind us. But it is up to us to rally them. We just can’t expect everything to run smoothly if we don’t play to our limit. We didn’t last week and deserved to get punished.
“It will be different tonight. The players know that if they lose it is more or less goodbye to this year’s Heineken Cup campaign.”
Meanwhile, five thousand more tickets for the ninth Heineken Cup final will be put on sale immediately following an unprecedented rush of interest in the last week. The first tranche of 5,000 tickets that were put on public sale for the final at Twickenham on Sunday, 26 May have sold out.
Tournament organisers ERC were told by ticket agents Ticketmaster that all 5,000 went before a ball was kicked in this season’s competition last Friday night. “We expected business to be brisk, and we are delighted that all available tickets have sold so quickly,” admitted ERC chief executive Derek McGrath.
ULSTER: Cunningham; Topping; Stewart, Steinmetz, Howe; Humphreys, Doak; Kempson, Sexton, Best, Frost, Longwell, Ward (capt), Best, Wilson.
Replacements: Shields, Moore, Mustchin, McWhirter, Campbell, Larkin, Wallace.
STADE FRANCAIS: Corleto, Lombard, Hernandez, Liebenburg, Bergamasco, Dominguez, Pichot, Marconnet, August, Lemoine, Auradou, Marchois, Moni, Martin, Rabadan.
Replacements: Blin, De Villiers, Bado, Bergamasco, Poulain, Skrela, Vass.