The Boston Celtics are 46 days away from returning to their confetti-cleared parquet to begin defending their NBA championship in search of a repeat finish, which the organization hasn’t accomplished in over five decades.

It’s immensely more difficult to seize a second-consecutive title, however, Celtics head coach Joe Mazzulla isn’t lowering the bar. Boston retained all but two members of its championship roster — Oshae Brissett and Svi Mykhailiuk weren’t re-signed — while creating an expensive starting lineup with ownership tied to $930 million in extensions given to Jayson Tatum, Jaylen Brown, Kristaps Porzingis, Jrue Holiday and Derrick White. Nevertheless, ESPN’s Brian Windhorst isn’t convinced.

“It’s just hard to maintain (that edge),” Windhorst said Friday on ESPN’s “NBA Today.” “We’ve had seven consecutive years of not having the back-to-back champion. The last time we had a back-to-back champion was the Warriors when they had arguably one of the greatest teams of all time in ’17 and ’18. I expect the Celtics to give a great title defense, but it’s not going to be the same once you’ve won the championship.”

Boston lived up to its hype a year removed from squandering a picture-perfect opportunity to secure an NBA Finals date with the Denver Nuggets by falling to the less-talented Miami Heat in the Eastern Conference finals. That loaded up the pressure on the Celtics, coupled with their blockbuster additions of Porzingis and Holiday, but the team didn’t falter. Boston led the league in regular season wins (64), notched a record-setting 17 25-point victories and captured the franchise’s 18th banner.

Windhorst referenced nine-time champion Pat Riley, who’s best known for winning four as head coach of the iconic “Showtime” Los Angeles Lakers.

“We know through history of the NBA and human nature it’s hard to maintain that (edge),” Windhorst explained, per ESPN. “I’ll go back to something Pat Riley once told me about his famous declaration. You remember? 1987, he’s at the parade in LA and he announces, ‘We’re gonna do it again.’ He pretty much guaranteed they’d come back and win it in ’88. There was a reason he was doing that. It wasn’t just to get a big cheer. He was telling me one time that just because the previous two times the Lakers won the title, he noticed that the team lost its edge going into the next season.”