NASCAR racer Brain Vickers has been hospitalized for an undisclosed medical condition and will be missing this week’s race in Delaware.

Red Bull Racing team representatives say that the 26-year-old has been hospitalized for tests last Wednesday. The team replaced Vickers with Casey Mears for the race at Dover International Speedway.

“Our main concern right now is with Brian and his health and recovery,” explained Jay Frye, General Manager of Red Bull Racing. “All things are looking good at the moment. This is just a minor setback. We appreciate Casey filling in this weekend and know he will represent the team well.”