CHARLOTTE, N.C. — Three-time NASCAR champion Tony Stewart was hospitalized Tuesday with a back injury and Stewart-Haas Racing said the team was unsure of the extent of his injuries just a week before he is expected in Daytona to prepare for his final season in Sprint Cup.

The 44-year-old Stewart was injured Sunday during an accident while he was riding an all-terrain vehicle somewhere on the West Coast, SHR spokesman Mike Arning told The Associated Press. He was being evaluated at an undisclosed hospital and able to move all extremities.

Arning indicated Stewart’s condition will not be updated again until Thursday. Stewart was in Arizona on Saturday night at the Barrett-Jackson auction in Scottsdale and interviewed on live television from the event.