The Belgian crashed while training on January 2, fracturing his hip in the the accident, and has been unable to return to racing since then.
Adding to the 32-year-old's frustration is that he has yet to turn a pedal in anger for Wanty-Groupe Gobert after only joining the team at the start of the 2018 season on the back of seven years with the various iterations of the Lotto Soudal outfit.
Luckily, De Clercq signed a two-year contract with his new team, and hopes to be able to return from his hip operation in time for the 2019 season.
According to Wanty team doctor Joost De Maeseneer, De Clercq suffered a severe fracture of the head and neck of his left femur, although it was initially hoped that he would have been able to resume light training some time in March.
But the climber also required a second operation in June, according to Het Laatste Nieuws, when damaged pieces of cartilage were removed.
However, complications since then have meant that De Clercq will have to have a full hip replacement next week.
"Unfortunately, at this time, a total hip replacement is the only solution left to recover," he tweeted on Monday, while vowing to fight his way back into the pro peloton.
De Clercq is best known for his stage victory at the Giro d'Italia in 2011 when, in his first year as a professional – and having only started cycling competitively in 2009, having come from a background in athletics – he out-sprinted the late Michele Scarponi and Roman Kreuziger on the mountainous stage 7 from Maddaloni to Montevergine de Mercogliano.
Since then, De Clercq's only other pro win has been a stage victory at the 2015 Tour de Pologne, although he also finished second overall at that race, and second overall at the 2016 Tour de l'Ain.
When signing for Wanty-Groupe Gobert from Lotto Soudal last year, De Clercq said that his intention was to share his experience with the squad's younger riders.
"I look forward to working with young talent like Guillaume Martin," he said at the time. "In the coming two years, I'll combine going for my own chances and assisting riders like Martin in the mountains."
Last months we tried all we could to save my hip after a bad crash in January. Unfortunately, at this time, a total hip replacement is the only solution left to recover. This implicates another surgery next week, but I'll fight my way back into the peloton!— Bart De Clercq (@Bartdc86) October 8, 2018