Kennedy had initially retired from cycling after the Tour de Ardeche in September but found herself back in action due to an injury Georgia Williams sustained in the inaugural Paris-Roubaix last weekend.
The 33-year-old had been away just 19 days before finishing 39th in Stage 1, while teammate Sarah Roy crossed the line in 11th place.
Kennedy had planned to continue supporting her teammates at the British event, starting with Stage 2, but soon withdrew from the event after inclement weather raised concerns over potential re-injury.
Having sustained multiple fractures in a crash at Liege-Bastonge-Liege, the risk of competing in the second stage simply outweighed the reward for the Australian.
“Lucy had prepared for Ardeche as her final race,” Team BikeExchange press officer Lucy Martin said.
“Calling her up was simply a necessity to be able to start with six riders.
“As expected, she wasn’t 110% prepared, and it is a race at a very high level. Under the harsh conditions today, she suffered and was scared to crash and break any bones.”
“Now that I’ve definitely done my last professional race, I can start to reflect on my career," Kennedy said.
"While I am proud of my handful of victories and successes, I don’t think those are the moments that I’ll look back on most fondly.
“The relationships I’ve built with teammates are some of the strongest of my life because we’ve shared such a unique path and I’ll forever be grateful for them.
"I feel proud to have been part of the GreenEdge team for the entirety of my career; I could not imagine feeling at home anywhere else, while being so far away from my Australian home.
“I’ve packed some of the most incredible and the most difficult parts of my life into the last four years.
“It has certainly shaped who I am. I thank everyone who has been part of this amazing journey. I’m now looking forward to some rest and relaxation before shaping my life after professional cycling."