Italian Conte was shown a red card during last week's draw with Sporting Lisbon for his reaction after an injury-time goal was disallowed.
Spurs head to southern France knowing they will reach the last 16 if they avoid defeat to the 1993 winners on Tuesday.
"It's a change that's difficult but we have to prepare ourselves all together before the match," Stellini told reporters.
"It's a totally different world because normally the days before the game, Antonio will do all his preparation himself, alone.
"But now, we have to do this all together so it changes everything. We have to work on the strategy and this can become complex," he added.
The north London outfit will come up against former Arsenal attacker Alexis Sanchez (33) as well as Matteo Guendouzi (23), Nuno Tavares (22) and Sead Kolasinac (29), who have also spent time at the Emirates Stadium.
Chile's Sanchez lost one derby between the sides in seven meetings.
"Beating Spurs every time was a great joy," Sanchez told reporters.
"It was very special and those are memories that I hold dear to my heart," he added.
Marseille will reach the next round if they win the fixture.
"Every single player has motivation to play and win," Sanchez said.
"We all want to bring the victory back," he added.
