CHARLOTTE, N.C. -- The undisclosed illness that has sidelined Daytona 500 champion Trevor Bayne with blurred vision and other symptoms for more than three weeks will keep him from driving in Saturday's All-Star race at Charlotte Motor Speedway.
"Although we would like for Trevor to be on the track this weekend, we want to make sure that he is fully back to prime condition before he goes out to compete with the best drivers in the world," Roush Fenway Racing president Steve Newmark said Thursday.
Bayne tested Wednesday at Rockingham Speedway for Roush Fenway Racing, which owns Bayne's contract and fields him in the No. 16 Ford in the Nationwide Series.
RFR officials said Bayne, who qualified for the All-Star race by winning the Sprint Cup opener at Daytona in the No. 21 he drives on a limited basis for the Wood Brothers, did not appear at full strength after more than three weeks of non-activity while undergoing tests.
Bayne's Nationwide car did not make the trip to Iowa for Sunday's race and will not be entered with any driver. The Wood Brothers will not replace Bayne in the All-Star race even though they have that option.
"He has been undergoing tests and out of his routine for almost a month now," Newmark said. "With that disruption in his schedule, he has not been able to take part in our daily training activities and he's going to need a little more time to get acclimated to the strenuous demands of NASCAR racing.
"Obviously, we would love to have him back out on the track, but we are not prepared to do that until we are sure that he's 100 percent."
Bayne has been having symptoms of blurred vision, pain in his left shoulder and elbow, fatigue and periods of feeling nauseous since early last month.
The symptoms originally were linked to an apparent insect bite received the Sunday after the Martinsville Sprint Cup race, but there has been no definitive diagnosis even after Bayne spent several weeks undergoing tests in the Mayo Clinic.
"They still are a little challenged to understand why he has the problem he has," team owner Jack Roush said Sunday at Dover. "It may be some medical condition that is not too bad, subject to medicine and treatment.
"The only thing they know for sure is he had a bug bite, that he had a very strong reaction to it. It affected his arm and shoulder. The appearance of it is it gave him some blurred vision. It is unknown what the rigor of all the temperature and stress and strain and driver has in the seat."
Although the symptoms had subsided enough that it was initially thought Bayne could compete in the All-Star race, it was decided after Wednesday's test he probably needed another week to recuperate and gain back his full strength.
David Newton covers NASCAR for ESPN.com. He can be reached at email@example.com.