"I'm so excited to be in the NFL," he says. "I'm just trying to get into my playbook and learn a new offence for my first mini-camp. We have a rookie camp with all the new guys this weekend. The veterans come in two weeks later, we start practising double days with full pads and then the season starts. It's a full-time job from now on."
But while the thrill of being drafted still hasn't worn off, Ellison apparently came close to landing a spot with the reigning Super Bowl champions, the New York Giants.
"After the teams worked me out, they all seemed really interested in me," he says. "The Giants actually flew me over to see the team and facility.
"The Vikings never worked me out at all but I had an interview with them at the NFL combine. I couldn't tell where I'd end up but I'm just excited to be in the NFL - I don't care where I'm at."
Born at Portola Valley, California, Rhett briefly attended St Andrew's College in Christchurch - his dad's home town - during his teens and dabbled in rugby and cricket.
"Dad and I would throw the rugby ball around in the park and I used to play pick-up games against other kids but I could never get used to passing the ball backwards."
Riki made his name as a linebacker, firstly at USC and then with the San Francisco 49ers, before ending his career with the Los Angeles Raiders. All three were elite teams of their time but the 49ers were legendary. Coached by Bill Walsh, they were led by quarterback Joe Montana and running back Jerry Rice - both since admitted to the NFL Hall of Fame. Ellison was drafted in the fifth round at the insistence of USC conditioning coach Jerry Attaway and former team-mate Ronnie Lott, another of the 49ers to reach the Hall of Fame.
Minnesota have taken a similar chance on Rhett Ellison but he enters the league under very different circumstances. Last season, the Vikings were terrible - not quite the worst team around but not far from it.
Unlike his father and Dixon, who both played in the trenches with little hope of seeing the ball, Rhett is primarily a tight end, one of the most skilled positions on the football field. His role is either to protect the quarterback by blocking the opposition's pass rushers or make himself available as another passing target.
At 1.95m and 115kg, he also plays on special teams, contesting kickoffs, punts and field goal attempts. As a Trojans captain in his senior year, Ellison earned Pac-12 conference honours as a special-teams player, and won USC's Leadership and Co-Lifter of the Year awards.
"He has a lot of ingredients," says Riki. "But I think his leadership abilities also opened people's eyes and they started realising the benefits of putting someone like him in a locker room filled with stars."
Rhett has a four-year contract with Minnesota and the rookie minimum salary is $440,000 so, although he still needs to earn his place, they've committed to finding one for him. "They had a tough season last year but from what the coaches tell me, they want to win," he says. "They're hungry and they've got a lot of talent. I'll do whatever I can to get on the field and help them out."
