This Lion’s biggest play could save a young girl’s life.

Four tiny, circular scars and a few days of soreness in his lower back were the only evidence of Matt Popek’s potentially lifesaving sacrifice. With luck, a phone call sometime soon will confirm that his sacrifice paid off.

It was a few days before Thanksgiving when Popek, a junior running back on the football team, donated bone marrow to an anonymous 9-year-old girl battling acute lymphoblastic leukemia. The donation came about after Popek and his teammates hosted a campus bone marrow registration drive last spring; the 20-year-old criminology major was the only Lion whose DNA matched someone in the national Be the Match registry. Popek doesn’t know much about the recipient other than her age, gender, diagnosis, and that her status is “urgent.” Given the effects of radiation and chemotherapy, the girl’s body will be reliant on healthy bone marrow to survive. “There’s a much more scientific term,” Popek says, “but the term I like is ‘reboot.’ The clean cells from my marrow will fight the cancer, so it basically reboots her system.”

Popek downplays how much of a sacrifice his donation really was: “I can honestly say my experience wasn’t that bad—the soreness felt like the day after a lower-back workout.” Toughness of the sort Popek displays on the football field no doubt helped him handle the pain of having liquid marrow withdrawn through needles inserted into his pelvic bone. When we spoke in December, his only remaining discomfort was impatience as he waited for good news. Be the Match representatives were set to keep him updated on the recipient’s progress, and if all goes well, he hopes to eventually get a call telling him that she’s cancer-free. If so, Popek hopes to meet the girl whose life he saved. In the meantime, he says, “I’m just happy I got to be that person who had a chance to help.”