Francois Duval's injured co-driver Patrick Pivato has undergone two operations in Sapporo's Higashi Tokushukai hospital and is now in a critical but stable condition.
The Frenchman sustained a fractured pelvis and tibia when the crew's Stobart Ford crashed into a barrier at high speed during SS6 of the Rally Japan on Friday.
During surgery to realign Pivato's pelvis, some internal bleeding was discovered, necessitating a second operation, which was completed at 1am local time this morning.
A statement from the Stobart team said Pivato had subsequently "made steady improvements" but remained in a critical but stable condition.
Duval was not injured in the crash, which occurred just after the crew had moved up to second place in the Japanese event.