While most 17-year-olds were spending their free time playing video games and hanging out, Common was perfecting his skills. There's no doubt that this led to his successful hip-hop career.

The Grammy-winning artist revealed how he began rapping thanks to a sports-related injury on this week's episode of "When I Was 17," airing Saturday at 11 a.m. ET.

"When I was 17, I went to high school at [Chicago's] Luther South, and I did well in high school," the MC said on the episode, which also features [article id="1674685"]T-Pain[/article] and "Twilight" star Alex Meraz. "I played basketball, but I got injured."

Common was hit in the eye during one of the games. Of course, that put him out of the game for a little bit, since it's kind of important to be able to see what's going on. So Common decided to use his time a little more productively than most other 17-year-olds.

"When I got injured, I couldn't play for a little while, so I started rapping more," he said. "I would be in gym class, and I would, like, get somebody to start beatboxing, and I'd just start freestyling."

Even at such a young age, Common's freestyling skills were unmatched. "He would be able to freestyle on any topic," his friend Marlon recalled. "We would change topics for him, and he would be able to talk about and rap about it. It was actually amazing."

He went by the moniker Rashid Cool at the time, and people knew he was a force to be reckoned with. "It was right around the time hip-hop was getting strong, so you get respect. A lot of people were like, 'Rashid Cool, you know he's good people,' " Common said.

"When I Was 17" -- this week featuring T-Pain, Common and Alex Meraz -- airs Saturday at 11 a.m. ET/PT on MTV.