Siena’s Santa Maria alle Scotte hospital issued an update late on Saturday on Alex Zanardi's condition, but a prognosis on the Italian's situation currently remains impossible.
Zanardi was airlifted to the hospital on Friday afternoon after suffering a traumatic impact with a truck during a handbike event in Italy.
On Saturday morning, the 53-year-old was in a "stable but serious" condition after undergoing two-and-a-half hours of neurosurgery as well as maxillofacial surgery to the face and jaw, and moved to intensive care overnight.
Dr Giuseppe Olivieri, the head of neurosurgery at Santa Maria alle Scotte, released another health bulletin on Saturday evening, and his words left no doubt as to the gravity of Zanardi's situation.
"The condition of Alex Zanardi is serious but stable," he said, quoted by the AP.
"He arrived here with major facial cranial trauma, a smashed face, and a deeply fractured frontal bone [forehead]. The numbers are good, although it remains a very serious situation.
"We won’t see what his neurological state is until he wakes up — if he wakes up. Serious condition means it’s a situation when someone could die. Improvement takes time in these cases.
"Turns for the worse can be sudden. The operation went according to the plan. It’s the initial situation that was very serious."
Dr Oliveri underscored the importance of the week ahead in terms of Zanardi's evolution, but a prognosis at this stage remains impossible.
"The next step is to try and stabilise him over the next week or 10 days. Then if things go well, he could eventually be woken up and re-evaluated.
"As I told his wife, he’s a patient who is worth being treated. As far as a prognosis of how he’ll be tomorrow, in a week or in 15 days, I don’t know. But I’m convinced that he should be treated."