Steve Mandanda admits Marseille need to be at their best if they are to progress in Europe this season.
Didier Deschamps' side are the reigning French champions, but have made a stuttering start to the 2010/11 campaign.
Their domestic struggles have provided them with a far from ideal build-up to a UEFA Champions League campaign which is due to get underway on Wednesday.
Marseille are set to face Russian outfit Spartak Moscow in their opening fixture, with it vital that they get off to a positive start.
Experienced keeper Mandanda admits as much, with the France international aware that a group that also contains Chelsea and MSK Zilina could pose a few tough tests.
"In our group, Chelsea have to be considered the favourites," he said in L'Equipe.
"Looking at second place, we will be in competition with Spartak and the Slovakian team. It won't be easy.
"We know how important the first match is. We have to win.
Mandanda added: "Do we want to win the Champions League? We have to be realistic. We are not among the favourites.
"Let's reach the knockout stages first, as we have failed to achieve that in our last three attempts."