EUGENE, Ore. (AP) — Defending Olympic champion Aries Merritt rushed back from a kidney transplant to be ready for Rio. He won't let Zika stand in his way, no matter how much his doctors object.

Qualifying in the 110-meter hurdles at Olympic Track and Field Trials begins Friday. Should Merritt make the U.S. team, he said he won't think twice about racing in Rio even though the mosquito-borne virus could pose a greater risk to him than most due to the transplant.

"They're very, very concerned. They've asked me many, times: 'Have you considered not going?'" said Merritt, who holds the world record in the hurdles (12.80 seconds in September 2012). "I'm like, 'Well, that's not an option. If I make it I'm going.'"

The reason is simple: At 30, he doesn't know if this sort of chance will come around again.

Merritt won bronze at last year's world championships in Beijing with his kidneys barely functioning because of a genetic disorder. He received the transplant from his sister less than a week later. He had another follow-up surgery in October because of complications.

He is still in the healing process.

"Doctors told me I was supposed to be running maybe next year, not this year," Merritt said. "I really don't have that option to skip Olympic Games. It's not something I can skip. ... I don't have time to be skipping stuff."

He got a late start on training because of the transplant and, other than a groin strain that cost him a few weeks, he says he's in competition shape.

"It's definitely been an uphill battle," Merritt said. "There are minor setbacks that happen. Every athlete goes through (something). It wouldn't be a journey if we didn't have something. It just can't be perfect all the time."

Merritt didn't let anyone know until just before worlds last August, but he was suffering from a rare genetic disorder that was diagnosed in 2013. For years, it turns out, his kidneys have been faltering, to the point where he ran the final at worlds on Aug. 28 at about eight pounds under his normal weight and with his kidneys barely functioning.

He finished 0.01 seconds behind Hansle Parchment of Jamaica for second. Sergey Shubenkov of Russia took gold.

"Competing at worlds last season with no kidney function was horrible," Merritt said. "There was a 90 percent chance I'd never run again. I just so happened to beat those odds. Kind of like the odds of going to the Olympic Games."

Contrary to a handful of golfers and other athletes who are skipping the Olympics because of fears of the illness, Merritt says he'll be there if he qualifies.

He'll take plenty of precautions: Long sleeves, insect repellent and plans to stay indoors as much as possible.

Other than that, there's not much he can do.

"We have Zika back in America," he said. "I haven't gotten it yet. I don't think it's that big of deal."