Deschamps told a news conference that Inter would be a tough nut to crack in Europe's premium competition.
"I have already warned that this side is not the one we saw in their last Serie A games," he said.
"They have great players, all internationals. They can hurt us with their offensive line-up: [Diego] Milito, [Wesley] Sneijder, [Giampaolo] Pazzini, [Diego] Forlan, [Mauro] Zarate. Individually, they're capable of everything," he said.
It does not mean, however, that Wednesday's game will be easy for Marseille.
"Their players don't make a lot of mistakes. We will have to be very vigilant, because they are very efficient," said Deschamps.
"It's the game we need to get back on track. Our team need adrenaline to play great games," he told a news conference.
Ranieri, who said he felt "supported" by Inter president Massimo Moratti, added that the Marseille clash was the perfect "moment to react."
