Mark Cavendish has suffered a fractured rib and injuries to his knees, hips, hands and some swelling on his face in a crash, his team has revealed.
Cavendish was taken to hospital during Wednesday's opening stage of the Tirreno-Adriatico in Italy.
The 32-year-old completed the stage but Team Dimension Data said he came down "pretty hard at around 55km/h".
"An X-ray found that he has a fracture of the seventh rib on the right side," added the team statement.
Cavendish, who has been selected by the Isle of Man to lead its road cycling team at the 2018 Commonwealth Games in April, did cross the finish line, but his time was outside the limit and is out of the Tirreno-Adriatico.
"The fracture's nice and stable and should heal well," said Dr Jarrad van Zuydam, who treated Cavendish after his crash.
"The plan was to let him start stage two.
"Unfortunately it was ruled he finished outside the time limit and so won't be allowed to take the start."
Cavendish withdrew from the Abu Dhabi Tour in February having sustained concussion and whiplash.
"It's frustrating to have crashed, particularly in light of the concussion that I sustained in Abu Dhabi," he said.
"But I'm just pleased that there's no major damage done.
"Despite the pain from my injury I was really looking forward to a fast second stage and naturally disappointed that I'm not going to be a part of it."