ABC News July 15, 2015

ESPYs 2015: Devon Still's Heartbreaking Speech About Daughter Leah's Battle With Cancer

WATCH: Devon Still Accepts Award on Behalf of His Daughter

Cincinnati Bengals defensive tackle Devon Still said tonight he felt like he was in a nightmare after his daughter Leah's initial cancer diagnosis.

Devon and 5-year-old Leah were honored at tonight's ESPY Awards with the Jimmy V Perseverance Award, presented by LeBron James. Devon has been by his daughter’s side during her battle with cancer, often sharing some of their special moments -- like fist bumps and pep talks -- on social media.

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In his heartfelt ESPYs acceptance speech, Devon said that during Leah's treatments, he'd go down to the hospital chapel and cry. He said he'd ask God why his daughter had to battle cancer instead of him.

"For every child out there that's battling cancer ... y'all are the real heroes," Devon said.

"Y'all never give up," he said.

"I am here today to let y'all know, as long as I have this platform I'm going to continue to fight for y'all," he said.

Leah did not attend tonight's ceremony, but she did appear in a brief video message, thanking everyone for their support.

Kevin Winter/Getty Images
Honoree Devon Still accepts the Jimmy V Award for Perseverance during The 2015 ESPYS at Microsoft Theater, July 15, 2015, in Los Angeles.