CHARLOTTE, N.C. -- Chris Buescher likely will replace Trevor Bayne in the Roush Fenway Racing Nationwide Series car for the second straight race as the Daytona 500 winner remains hospitalized for an undisclosed illness, sources told ESPN.com on Wednesday.
Bayne, feeling fatigued and nauseous, was admitted into the Mayo Clinic April 27. His symptoms at the time were believed to be related to an insect bite he suffered in early April following the Martinsville Sprint Cup race.
But Bayne said on Twitter during the weekend, "Don't think it's related to the bite . . . but we'll see! God has something cool going on that we can't see yet."
Despite numerous rumors about Bayne's condition -- which at times has included a rash as well as swelling and numbness in his left arm -- several sources said doctors have not made a final diagnosis and would not speculate on whether this could be career-threatening.
But sources said it is highly unlikely Bayne will be in the car for Friday night's Nationwide race at Darlington Raceway.
Bayne, 20, ranked fifth in the Nationwide standings before the Richmond race. He is now seventh, 45 points behind leader Justin Allgaier, and missing Darlington all but eliminates any chance for the Nationwide title.
Buescher, an 18-year-old developmental driver for Roush Fenway Racing, finished 17th in his Nationwide debut at Richmond. The No. 16 car fell two spots to 12th in the owners' points standings.
A final decision on whether to put Buescher in the car is expected to be made Thursday.
Bayne's next scheduled Cup race for the Wood Brothers is the May 21 All-Star race at Charlotte Motor Speedway.
The Wood Brothers had planned to run at Darlington, but announced last month they were running the July 2 event at Daytona instead.
David Newton covers NASCAR for ESPN.com. He can be reached at email@example.com.