"I'm 100% sure it will get done," Kekalainen said Wednesday, according to NHL.com's Tom Gulitti.
"We've been in this situation before where we've had RFAs that want to take their time to agree on a contract, and we respect that and they have that right," Kekalainen said. "But I'm confident he'll be signed before training camp starts."
It remains unclear when training camp will begin, but the NHL is targeting Jan. 1 as opening day for the 2020-21 campaign.
Dubois, 22, is a restricted free agent and paced the Blue Jackets with 49 points through 70 games in 2019-20 before notching a team-best four goals and 10 points over 10 playoff contests.
The 6-foot-3 center has tallied 65 goals and 158 points in 234 games since being selected third overall by the Blue Jackets in 2016.
Columbus has $9.22 million in projected cap space with no outstanding restricted free agents beyond Dubois.