Although Fenerbahce are in command of Group C with 10 points from four games and a five-point lead over Marseille and Borussia Monchengladbach, qualification for the last 32 could still go down to the wire.
Wins for Marseille and Borussia - who are at home to already-eliminated AEL Limassol - on Thursday would leave three teams battling for the top two spots on matchday six, when Limassol will host Marseille and the Bundesliga side travel to Turkey.
And Fanni hopes Fener will continue their attacking approach to away games at the Stade Velodrome, with the Turkish side having won 1-0 at Limassol and 4-2 at Borussia in the group so far.
"These teams are preferred because it opens up more gaps for us and we are exposed to less counter-attacks," Fanni told his club's website.
"Against such teams we provide, in general, more opportunities. Against teams who do not play, we have not been successful in recent times."
The reverse fixture in Istanbul ended 2-2 after OM scored twice in the last eight minutes to snatch a point, and Fanni added: "They will be wary of us. We are able to do many good things. We do not doubt our quality, we know what we can and we must implement."
OM will be out if they lose and Borussia beat Limassol and the statistics make for mixed reading for the French side.
Fenerbahce have lost their last four games in France since beating Bordeaux 3-2 in 1985, but the Yellow Canaries have won three of their last four European away games.