It was unclear when Fantilli was drafted if he would sign with Columbus or return to Michigan for another season.
"We were discussing it pretty quick," Fantilli said. "I had a pretty good feeling and I think [Blue Jackets general manager Jarmo Kekalainen] said he had a pretty good feeling as well. Going through the interview process at the combine and everything that way, I had a really good relationship there and hopefully we'll continue to develop that, but I think it was trying to feel ready. I feel I'm ready. I thought we were both confident, so that's what led to the decision."
"It was a brief discussion," Kekalainen said. "I think we both felt that he was ready to take the next step, the next challenge. We were very clear on that, in the conversations with them. We've watched him all year on different levels in college, in the world juniors, world championships playing against mostly NHL players.
In Columbus, Fantilli will join fellow Michigan alums defensemen Zach Werenski and Nick Blankenburg, and forward Kent Johnson.
"We are extremely happy for Adam and his family," Michigan coach Brandon Naurato said Saturday. "This is an amazing opportunity for him in Columbus with a great organization, one of the best coaches of all time (Mike Babcock, hired Saturday), and a lot of Michigan men to help show him the ropes early in his NHL career."
Fantilli also helped Canada win the gold medal at the 2023 IIHF World Junior Championship and the 2023 IIHF World Championship.
His play at the World Championship, where he had three points (one goal, two assists) in 10 games, stood out to Blue Jackets general manager Jarmo Kekalainen.
"He's a big man (6-foot-2, 195 pounds) as you can see, he's physically ready," Kekalainen said. "He's mentally ready to take the next step and the next challenge and that was our position and he agreed. The entry level contracts are not rocket science so that didn't take very long. There's plenty of comparables there where he was drafted and we agreed on it very quickly and got it signed today."
"At the beginning of the tournament, I was kind of feeling out our systems, feeling out being a locker on it, learning how to fit in with those types of guys and towards our system," Fantilli said. "Once I became confident in our system and playing the defensive side of it, I was able to be a bit more creative offensively and take a couple more chances that way because I knew the system better.
"I knew how to recover better, and I thought that helped me play a lot better in the medal rounds. Towards the end of that tournament, I felt more and more ready and obviously, the NHL is the best league in the world and I don't know how it's going to compare to it because I don't have any games to play, but I did get a pretty good sense playing around and being with guys like that."
NHL.com staff writer Mike G. Morreale and independent correspondent Craig Merz contributed to this report