Depleted Montpellier look to maintain lead
Vern Cotter's side have made a stunning start to the campaign and hold a two-point lead over surprise challengers Lyon at the summit.
But former New Zealand flyhalf Cruden picked up a rib injury in last weekend's 54-10 thrashing of Brive and joins South African prop Du Plessis, as well as backs Joe Tomane and Timoci Nagusa, on the sidelines.
Montpellier will also be facing their former wing Marvin O'Connor for the first time since the Frenchman joined Stade Francais at the start of the season.
The 26-year-old of Australian descent was shown the door by Montpellier after seeing his 2016-17 season cut short in November last year by a dislocated knee.
"From then on, it was the beginning of a descent into hell," he told AFP.
"The new staff had to make a choice. They brought in star players and had to make cuts for the salary cap. I had hardly played that season, and I paid the price,"
Stade's miseries have continued this year as after seeing a proposed merger with Racing 92 fall through, they have lost four of their opening six matches, including two at home.
The only real bright spot of the season so far was a 35-24 victory over La Rochelle at the Stade Jean Bouin, when O'Connor dived over for the fifth and final try.
Now the capital club will be hoping to prove that wasn't a false dawn, having picked up their second win at Pau last time out.
Despite their injury troubles Montpellier are still a formidable outfit, with South African international Francois Steyn set to take Cruden's place at fly-half.
Fijian wing Nemani Nadolo will be hoping to back up his performance against Brive last Sunday, when he ran in his first tries of the season with a hat-trick.
Struggling champions Clermont travel to third-placed Toulouse on Sunday, as they continue their search for a first away victory of the season after a 29-23 loss at Castres.
They are already five points adrift of the top six and have shipped 112 points in only three games on the road.
"We had big deficiencies there and it's starting to annoy me," coach Franck Azema said after their latest defeat last Sunday.
"We have to find solutions together and soon go back to the drawing board so that we don't become frustrated like that constantly."
Azema will be able to welcome back French international centre Damian Penaud this weekend, but Fijian wing Alivereti Raka is out with a heel injury.
Lyon will be looking for a fourth straight win on Saturday when they visit lowly Agen, who are second-bottom in the table.
Depending on the Montpellier result, a win could send Lyon top of the division in just their second season since promotion.
The other heavyweight clash of the seventh round of matches sees last season's regular-season table-toppers La Rochelle face Racing on Sunday.
Fixtures:
Saturday
Stade Francais v Montpellier
Bordeaux-Begles v Toulon
Brive v Castres,
Oyonnax v Pau
Agen v Lyon
Sunday
La Rochelle v Racing 92
Toulouse v Clermont
Agence France-Presse
