The core has changed over the years. It used to include players such as forward Milan Lucic, who was traded to the Los Angeles Kings in 2015 and signed as a free agent with the Edmonton Oilers last summer, and defenseman Johnny Boychuk, who was traded to the New York Islanders in 2014 because of salary cap constraints. Those were crucial players and crucial pieces who, it seemed, might continue on in Boston for quite some time.
The core is smaller, older and more battle-scarred. It has seen what it can do at this level, the heights it can reach, and it has seen how it feels to spend the summer with a host of "what ifs?" It will again this year.
And even as Bergeron admits that the time has gone on, that the group knows what happens each time a birthday comes around, it still believes in itself, even with the evidence of the past four seasons in front of it. It also believes that Pastrnak and Carlo and McAvoy and others, like forward Jakob Forsbacka-Karlsson, potential stars in the making, might be the antidote to the encroaching years.
"We all know that we're getting older, but I think that just drives us more to want to get back there," Marchand said. "We're hungrier to get back there. We know that time for our careers could wind down at some point.
"When you've been in it, and I was fortunate enough to win my first year, and the only other time we've been past the [second round] was the year we went to the Final again. So it doesn't happen all the time and you really have to cherish and take advantage of the time you do get."