De Gendt, crossed the finish line 5:29 behind stage winner Andrew Talansky (Garmin Sharp) and is at 5:34 in the overall standings.
"We pretty much had the most dangerous part of the descent behind us," he told Sporza, before explaining that when the rider in front of him crashed, he was unable to avoid him and collided.
"I had a lot of pain in my shoulder and neck, but there is nothing broken," De Gendt continued. "I also got hit on my hip. It will be seen whether that will affect my legs or if I suffer on the bike tomorrow."
With seven climbs ahead on Stage 4, De Gendt said that he will get a good indication early as to the ramification of the crash for the rest Paris-Nice.
While the 26-year-old's setback has ruled him out of GC contention, he remains optimistic that he will be able to try his luck in a breakaway over the coming stages.
"If a breakaway fails tomorrow, I can try again Friday or Saturday," he said. "And for the rest I want to help my teammate [Lieuwe] Westra."
Westra suffered his own misfortune, with equipment failure in the dying kilometres of the 170.5km stage. He finished in the chase group, seven seconds behind the leaders, and remains just six seconds back on new race leader, Talansky.
In other good news for the Dutch team, Martijn Keizer became the new leader in the King of the Mountains classification, from teammate Bert-Jan Lindeman. Keizer, who was in the day's early break with Sébastien Minard (Ag2r), Mads Christensen (Saxo Bank) and Alexis Vuillermoz (Sojasun). Keizer was first man across the line on the Col de Potey and Côte de la Forêt de la Comté but the quartet's lead was reeled in, with his efforts just enough for a one-point lead over Andriy Grivko (Astana) who took the spoils on the Côte de Mauvagnat.