Ineos principal Dave Brailsford confirmed to French television that the four-time victor will not start the Tour next month following a harrowing, high-speed crash during a training ride ahead of the fourth stage at the Critérium du Dauphiné.
Froome was treated by medical staff from a race ambulance that was near the scene of the crash, Brailsford said.
"He's in a very, very serious condition and he could hardly speak. It'll take quite a long time before he races again".
"He crashed in the downhill section of the course at high speed".
Brailsford later added in the statement that the team's primary focus was ensuring that Froome gets the best care. He hit a wall.
"One of our big strengths on this team is coming together in hard moments, and we will ensure we do everything possible to support Chris and his family", he said.
"One of the things which sets Chris apart is his mental strength and resilience - and we will support him totally in his recovery, help him to recalibrate and assist him in pursuing his future goals and ambitions".
He went on to further Tour de France wins in 2015, 2016 and 2017, he also won the 2017 Vuelta a Espana and the 2018 Giro d'Italia, making him the greatest Grand Tour rider of his generation.
Froome was eighth in the overall classification after three stages of the eight-day race, just 24 seconds behind leader Dylan Teuns.
The news comes as a huge blow to the four-time Tour de France Champion, who had looked in decent form in the opening three stages of the Dauphine as his preparations continued for the 2019 Tour de France, where he was expected to be joint team leader with defending champion Thomas.
"He's not going to ride the Tour".
This year's Tour de France embarks from Brussels on July 6 and the loss of the iconic four time victor will shake up ambitions at several teams.