The Australian came through Monday’s rest-day and started to stage 4 to Mount Etna but, according to his team, he was forced to quit the race midway through the stage.
Dennis came into the Giro with aspirations of a high overall place on GC but those plans were ruined after the late crash on stage 3. The former UCI Hour Record holder fell on his right side during a frantic hour of racing in cross-winds and, although he was able to remount and finish the stage, injuries proved to be worse than first thought.
After the crash BMC’s doctor Dr Giovanni Ruffini said: "Rohan Dennis went down on his right side at a high speed so naturally he has a fair bit of road rash and superficial contusions. He has a sore neck which is a result of the crash but usually, it's nothing the team's physiotherapist can't fix."
At the time Dennis complained of a stiff neck and a headache.
BMC Racing will now be entirely devoted to Tejay van Garderen and his GC challenge. The American is riding the Giro d’Italia for the first time in his career and has finished in the top-five twice at the Tour de France.