Aru had been named as the co-leader of UAE Team Emirates with 21-year-old Slovenian sensation Tadej Pogačar ahead of the race, but hasn't looked anything like his 2015 Vuelta-winning form in the racing so far at the Tour.
While the team have had a great opening week to the Tour, with Alexander Kristoff claiming the opening stage and yellow jersey, and with Pogačar adding another stage win along with a serious tilt at the yellow jersey.
The disappointing withdrawal was underscored by a savage assault from UAE Team Emirates former manager, Giuseppe Saronni, now employed by the squad as an advisor. The two-time Giro d’Italia winner made comments that appeared to be stigmatising old-fashioned concepts of mental illness and Aru’s character.
"Aru disappointed us," said Sarroni speaking on Italian broadcaster RAI. "He has problems, also psychological problems. He doesn't react at first difficulties, he goes down, he doesn't have that character. We should do evaluations on who took the decision to bring it in Tour de France."
Aru has had a succession of injuries since he was last finished in the top 10 of a Grand Tour, a knee injury, endofibrosis that had to be corrected with illiac artery surgery and a bout of cytomegalovirus. He had said, hyperbolically, earlier in the season that he was pedalling hard enough to break his bike, but that feeling hasn't translated to this year's Tour.
"His retirement is a great damage for Pogacar," said Sarroni. "He had the Tour de France on the program, but if he is not in good condition there must be someone to tell him that he cannot participate. At this stage, Fabio could have been of help to Tadej, and his retirement is really a major damage."
Aru himself was distraught after the finish of the stage, as reported in the UAE Team Emirates press release.
“I really don’t know what is happening to me, I have no answers and this makes me suffer," said Aru. "I approached this Tour de France on my toes, and I had worked well. Not to go for GC, but to help Tadej in the best possible way and maybe, who knows, get some chances of my own if the opportunity arose.
"I had put in a series of encouraging performances in the run-up to this Tour de France, except the bad day I had in Lombardy. My training data also showed optimism in returning to a condition that allowed me to perform well, certainly the best numbers in the last three years."
Aru had run top 10 at all three lead-up races to the Tour de France, at Vuelta a Burgos, Mont Ventoux challenge and the Tour de l'Ain. Aru explained how his condition seemingly came out of nowhere.
"Also yesterday, talking to the team doctor, I told him that I was feeling better, and that I was confident for the rest of the race.
"Now I am here, stuck in a hole, without really understanding why."
"I feel like I do not deserve this because I have always been an exemplary professional and given my maximum commitment. The team does not deserve this either and I suffer a lot in not being able to make my contribution as I would like to.
"My future? Well I’m not thinking about it right now. I’m still processing the disappointment of today.”
The Tour de France continues after the rest day with a pancake flat stage on the western coastline of France from Île d’Oléron to Île de Ré. Watch the action on SBS, with the race starting on the SBS ŠKODA Tour Tracker at 9.20 AEST and the broadcast beginning at 9.30 AEST on SBS VICELAND, switching to SBS HD at 10.30pm.