Sam Hornish Jr. replaces ailing Denny Hamlin for Sprint Cup race at Fontana

A sinus infection that impaired Denny Hamlin’s vision has sidelined the driver of the No. 11 Joe Gibbs Racing Toyota at Auto Club Speedway, team president J.D. Gibbs announced roughly 30 minutes before the green flag in Sunday’s Auto Club 400 NASCAR Sprint Cup Series race.

Hamlin was replaced by Sam Hornish Jr., who had come to Fontana as a possible relief driver for Matt Kenseth, whose wife Katie is expecting the couple’s third daughter.

“He had a little sinus infection a while ago, but it probably started Friday,” Gibbs said of Hamlin, who was taken to a local hospital. “I think he could still drive, but he brought up that he was concerned about it and just wanted to make sure it was taken care of.

“He brought it up with doctors who said, ‘Hey, we’ve got to do this right away.’ Hopefully, it’s nothing, but he had to get it checked out.”

Hamlin has had nothing but ill fortune recently at Fontana. Last year, he suffered a compression fracture of his first lumbar vertebra in a last-lap wreck triggered by contact from Joey Logano’s Ford. Hamlin missed the next four races while his back healed.

Hamlin’s prospects of making the Chase for the NASCAR Sprint Cup won’t be affected by the illness, as long as he finishes in the top 30 in the series standings after 26 races. Because Hamlin qualified for the race on Friday, he is credited with participation in the event.

NASCAR also could make a medical exception at its discretion, should the illness cause Hamlin to miss any additional races.