The addition of Sergachev gives the Lightning a centerpiece among a core of promising young defensemen prospects, including Erik Cernak, 20, acquired in a trade with the Los Angeles Kings for goalie Ben Bishop on Feb. 26, and Ben Thomas, 21, a fourth-round pick (No. 119) in the 2014 NHL Draft.
Cernak and Thomas are likely to play this season for Syracuse, but Sergachev will have a chance to make the Lightning roster. He broke camp with the Canadiens last season and played four games before being sent down for his second season with Windsor of the Ontario Hockey League.
Sergachev has said he'd rather not go back to juniors for a third year but isn't putting any additional pressure on himself.
"I don't know, I'm a prospect and I haven't made the team or ever played a full season in the NHL," Sergachev said. "So I'm just like everyone, trying to make the team."
That said, Sergachev's initial taste of the NHL has him itching to get back as soon as possible.
"I have to have a good summer, first of all, I have to be stronger," he said. "I have to be faster to play in the NHL overall to be successful. But I also played a lot in juniors, two years for me, I think is a lot and in Russia I played one year too.
"So I played a lot in juniors and I learned a lot from Windsor … so I think I'm ready for the NHL."
Sergachev said he models his game after Drew Doughty, the three-time All-Star and 2016 Norris Trophy winner for the Kings. Sergachev said he was frustrated by being traded at first but quickly realized the opportunity he has with the Lightning.
"It's amazing that this team wants me more than Montreal, and they want me to come play in the NHL and they want me to try to help them," Sergachev said. "That's why I love this team. Montreal needed Drouin, he's from there, and I think this is the only way Tampa [Bay] would have traded him was for me.
"They asked for me."