Memo Gidley will need further surgery in the wake of his violent accident in this weekend's Daytona 24 Hours.
The American underwent an operation on injuries to his left arm and leg overnight but will need another procedure to address what was described in a statement as "an unstable fracture in his back".
GAINSCO/Bob Stallings Riley driver Gidley is being treated at the Halifax Health Medical Center in Daytona Beach along with Italian Matteo Malucelli, with whose Risi Ferrari 458 Italia he collided at the end of the third hour of the inaugural United SportsCar Championship race.
Malucelli, whose Ferrari had lost drive when it was hit by an unsighted Gidley, was kept in hospital overnight for observation.
A statement from USC sanctioning body, IMSA, said of Malucelli: "He continues to rest comfortably. An update on his condition will be provided later today [Sunday]."