Michael Sam Moving Forward, 'Going Back to Work'

— -- Michael Sam is returning to the football field this morning for the first day of training camp for the St. Louis Rams.

As the first openly gay player drafted to the NFL, he knows he has a lot to prove -- on and off the field.

"I'm going back to work," Sam, 24, said in an interview with "Good Morning America" co-anchor Robin Roberts on Thursday in Los Angeles.

Asked what he has been doing since draft day to prepare for his first day in camp, he replied: "Training, working hard. I lost 12 pounds since -- when I came into mini-camp…

"I'm doing my job. Don't you worry," he said, laughing.

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Sam was a late draft pick, and he said there was a moment during the selection process when he doubted he'd make it to the pros.

"I was like, 'Maybe I shouldn't have done what I did.' You know?" he said, referring to his thoughts at that time about whether he should have kept quiet about his sexual orientation.

"I had so many emotions going in my head. And then I felt a touch over my shoulder and it was Vito," he said, speaking of his boyfriend, Vito Cammisano. "And I was just, I was like, 'I don't care what happens. You know, I know I did the right thing in my heart. And whatever happens, happens. I'm just going to move forward.'"

His honesty about his sexuality earned him the Arthur Ashe Courage Award, and his touching speech when he accepted it at the ESPY Awards on Wednesday made numerous headlines.

Sam told Roberts that accepting the award was "nerve-wracking."

"There's so many others that's well deserving of that award .... so I share this award with everyone who has the courage to tell their parents, to tell their peers, to tell their friends -- anyone, that, 'Hey, I'm comfortable (with) who I am. I don't care what you think. This is who I am,'" he said.