Head coach Conte is confined to the stands at the Stade Velodrome after his red card against Sporting Lisbon last week in the wake of the VAR's decision to controversially rule out what would have been a last-gasp winner from Harry Kane.
The Italian will sit next to his brother Gianluca and relay messages to the bench during the game, but is not allowed in the dressing room and cannot speak to his players until 15 minutes after full-time.
That means he cannot have direct influence on proceedings in a game that Spurs cannot afford to lose if they are to qualify for the knockout stages.
Stellini, who stood in for Conte during another touchline ban at their previous club Inter Milan, said: "When Antonio is on the touchline, he lives with passion every game but probably he struggles more when he stays in the crowd and so it explains how Antonio lives his job.
"He's very passionate and if he cannot communicate with us he struggles a lot.
"It changes a lot. The presence of a coach like Conte, both before the game and the week leading up to it and during the match, is just indispensable - especially a tough match like this where it's going to be intense until the final whistle.
"It's a change that's difficult but we have to prepare ourselves all together before the match.
"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.
"However, we've already gone through this together in our time at Inter so we know what to do when he's not there.
"Luckily, I'm not there on my own. We've got the whole staff, such as Ryan Mason, alongside me so that makes me feel better."