The Montreal Canadiens don't have to find a center that comes in and runs their first line. They've figured out that Nick Suzuki with Cole Caufield and Juraj Slafkovsky is here to stay, but who will play with Ivan Demidov and Patrik Laine is the bigger question. Whether or not Laine is still in Montreal in October is another question for another day, but for now, we'll say that's who is on the next center's left side.
Sidney Crosby

Sidney Crosby is and always will be the No. 1 option for the Canadiens' second-line center role. Some might argue that Crosby and Demidov on a line could qualify for the "first-line" designation, but we'll give Caufield, Suzuki, and Slafkovsky the respect of saying it'd be 1A and 1B at the most.
Crosby joining the Canadiens has been an idea from the fans for years, knowing that he is a former fan in his youth and might want to check that dream off his list. There aren't many unchecked boxes on Crosby's list, and playing with the Habs might be the one that puts a perfect cap on his career.
It isn't the most natural mentorship fit, but Demidov's comments about Alex Ovechkin/Evgeni Malkin make me think he might take Sid the Kid's side in that career-long battle with The Great Eight. Crosby could be the mentor that Demidov needs to clean up some of the deficiencies in his game.
We've argued so many points for Crosby that we haven't even mentioned the most important one. He is still a point-per-game player, which is a massive upgrade over Alex Newhook or even Kirby Dach. The legend will be the hardest player on this list to pry away from their team, but if the Canadiens can do it, they must consider.
Mathew Barzal

Crosby is the dream scenario, but Mathew Barzal might be the most logical option. While Crosby won't give the Canadiens too many more years, Barzal offers a player who fits much better with the team's current age window. He is a 27-year-old right-shot playmaker whose career-high in points came in 2023-24 when he had 80 points in 80 games.
It was an injury-plagued year for the Canadian center, but he had nine points in 10 games before the injury that ended his season at the beginning of February. Players perform on the island and are forgotten, but the hockey world would appreciate Barzal if he came to Montreal.
The only concern I would have is how Barzal would play with Demidov and Laine. It'd be a trio that severely lacks defense, and the whole point of getting a second-line center is to keep Suzuki's together. A Barzal acquisition would likely start a domino effect of also upgrading to a more two-way player at left wing.
Bo Horvat

Bo Horvat makes sense for many reasons. He cleans up that issue of not enough defense on the second line, and would make it more of a complete line with Demidov and Laine. It gives the wingers the freedom to do their own thing in the offensive zone, knowing that Horvat is there to cover for them. One other positive is it wouldn't cost as much to acquire the former Canuck.
Any team will have to overpay for Crosby despite his age, because let's face it, he's Sidney Crosby. Barzal still has plenty of runway left in his career, and the Islanders won't give him up without a considerable return. Horvat is more of an expendable asset, and while it isn't the big swing fans may want, he's a puzzle piece that could lead the Canadiens closer to contention.