FORT COLLINS, Colo. (AP) The kid wearing No. 1 for Colorado State is listed on the roster as a 4-foot, 53-pound running back from a nearby elementary school.
Football prodigy? More like football inspiration.
Over the past two seasons, Miller's become one of them. He has his own number, a bio page on the team's website and a personalized trading card.
The 9-year-old means a lot to the Rams. And the Rams mean the world to him as he goes through round after round of chemotherapy to keep the tumors from growing.
''The room starts to glisten when he walks in,'' said senior defensive back Bernard Blake, whose team has a bye this week. ''He puts a smile on everyone's face because he's got the biggest smile from ear-to-ear you've ever seen.
''He's one of us.''
Miller joined the Rams in 2013 through an organization called the Friends of Jaclyn Foundation, which matches children fighting pediatric brain tumors with college and high school sports teams.
Last season, Miller was tight with offensive lineman Weston Richburg, who's now with the New York Giants. Mention Richburg's name and the Miller's voice instantly rises.
''He once gave me his football gloves!'' Miller exclaimed in a phone interview.
It's one of the many Colorado State mementos he has in his room, along with signed pictures and posters.
His most prized possession? Trading cards featuring, well, him.
Last April, Miller received his own 2014 Upper Deck ''Star Rookie'' card. He even had an autograph session, with several Rams players trekking to Denver to support their teammate.
This season, he's grown especially close with Blake. They email each other before games, with Miller typically closing with: ''Good luck today. We're going to win.''
They have, too.
At 9-1, the Rams are off to their best start since 1994. Things are going so well that Miller is already working on his mom and dad, Jody and Darin, to attend the bowl game.
He's as much as a teammate as anyone, and the team treats him that way, too.
Like after a last-second field goal to beat Utah State on Oct. 18, when Blake scooped Miller up as the youngster stood outside the locker room, placed him on his shoulders and brought him inside, where the entire team sang the school's fight song together.
''Jack's been through so much,'' his mom said. ''Being a part of this team has added some fun childhood memories that he's going to remember forever.''
Miller has been in and out of hospitals since he was born. He underwent two surgeries to fix a heart defect by the time he was a month old.
When he was 3, Miller and one of his sisters each caught a virus. His sister quickly bounced back. Miller didn't.
A scan revealed a large mass in his brain and he had surgery on Easter of 2008 to remove about a third of the growth. He was on chemo for the next 15 months to keep the tumor from growing.
For over two years, the tumor stayed the same size. Then, when Miller was in first grade, it grew again.
Since then, he's been on one form of chemo after another. He recently went off the treatments, though, to give his kidneys a time out. The plan is to start chemo again at the first of the year.
''He's used to going to the hospital once a week. It's our new normal and we have to make a life with it,'' his mom said. ''But you still have to let him be a kid.''
On his trading card, he's listed as a running back. He's wearing an oversized Rams helmet in his picture and crouching down as if he's about to take a handoff from QB Garrett Grayson.
Of course, Miller's smiling.
This made his grin bigger last weekend: The Rams appearing back in the polls for the first time since 2003. He waited by his computer all morning, refreshing and refreshing until his team appeared, just like a true teammate.