The Montreal Canadiens went many years without having a first line center. There were many years where Saku Koivu filled the role admirably, but was far from one of the best centers in the league.
Then there was the lengthy David Desharnais era. He was a serviceable player but not the best option to be centering a line with sniper Max Pacioretty. He was the best option that the team had at the time.
Recently, Phillip Danault has been asked to fill the role of top line center. Danault is a solid two-way center who scored a career high of 53 points.