DOVER, Del. -- Trevor Bayne will test this week at Gresham Motorsports Park in Georgia before a final decision is made on whether the Daytona 500 champion can compete in Saturday's All-Star race at Charlotte Motor Speedway.
Team owner Jack Roush said Sunday at Dover International Speedway that Bayne has made "a lot of progress" with the symptoms from his undisclosed illness. He said the symptoms beyond pain in the left shoulder and elbow and periods of feeling nausea and fatigue have included blurred vision.
NASCAR medical consultant Dr. Jerry Petty is monitoring the situation and will make a final decision on clearing Bayne for his return after the test.
"If he feels like it, he's going to be in the Wood Brothers car in the All-Star race," Roush said of Bayne.
Roush said no decision has been made on whether Bayne will compete in next Sunday's Nationwide Series race at Iowa even if he does drive in the All-Star race.
Bayne has missed the last three Nationwide Series races. He spent more than a week at the Mayo Clinic undergoing tests for what were originally believed to be symptoms from a bug bite received last month after the Martinsville Sprint Cup race.
Roush said no definitive diagnosis came from the tests.
"They still are a little challenged to understand why he has the problem he has," Roush said. "It may be some medical condition that is not too bad to 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."
David Newton covers NASCAR for ESPN.com. He can be reached at email@example.com.