In this Oct. 9, 2017, file photo, Boston Celtics’ Kyrie Irving, left, and Gordon Hayward look on from the bench during the first quarter of a preseason game against the Philadelphia 76ers in Boston. Last season, hopes were high for the Celtics in the preseason with a new-look roster that included Irving and Hayward. Five minutes into the season opener everything changed with Hayward’s gruesome leg injury. It happened again late in the season with Irving was lost to knee surgery. With both back and healthy, Boston is embracing being called the presumptive favorites in the Eastern Conference. (AP Photo/Winslow Townson, file)

BOSTON — The band is back together in Boston.

Or, at least, it’s healthy again.

Hopes were high for the Celtics going into last season thanks to a revamped roster that included All-Star additions Kyrie Irving and Gordon Hayward.

Everything changed five minutes into the season with Hayward’s gruesome leg injury. Expectations changed again late in the season when Irving was also lost for the year following a pair of knee surgeries.

Without them, Boston finished the regular season with 55 wins and made the Eastern Conference finals. A Game 7 loss to the Cleveland Cavaliers ended a playoff run that saw veteran leadership from Al Horford, the emergence of Jayson Tatum and Jaylen Brown as budding stars and growth from Terry Rozier and Marcus Smart.

Celtics president of basketball operations Danny Ainge was able to keep the group intact during the offseason, re-signing the most vulnerable asset in Smart.

This preseason brought more welcome news when Irving publicly proclaimed his desire to stay in Boston. He stood at midcourt at the TD Garden and told a group of season ticket holders: “If you guys will have me back, I plan on re-signing here.”

The collection of talent makes the Celtics presumptive favorites in the East with LeBron James no longer lurking in Cleveland.

Coach Brad Stevens said his job will be to harness the energy on this roster, not restrict what guys do.

“We don’t want to set limits or ceilings on people,” he said.

It was made “very clear,” Irving said, during his time in Cleveland that he wasn’t the face of the franchise. Entering his eighth NBA season, he has openly referred to himself as the leader of this young Celtics team.

His teammates, including Horford, are happy to grant that stature to the five-time All-Star who won a title with Cleveland. Irving said being around so a hungry group drives him.

“It gives me a lot of confidence as the quarterback of the team,” Irving said. “This is a lot of talent that I’m being thrown out there with. A lot of responsibility that’s being put on my shoulders to lead this group, which I willfully accept.”

Here are some things to watch for this season:

COMEBACK KID: Whether this team ultimately can show enough moxie to make Boston’s first NBA finals since 2010 may hinge on how well Hayward plays during his comeback season.

He’s acknowledged having to mentally shake off rust and rediscover his timing. He also must find his place on a team that had to find a way to play without him last season.

He and Irving were presented as a dynamic duo of sorts prior to last season. Now both will get their chance to see how all the pieces fit together.

Hayward said he’s waited all summer to take on the challenge.

“There’s gonna be hiccups along the way… When you don’t play basketball for a year those things happen,” he said. “I’m gonna have to go at it and attack it.”

POSTIONLESS LINEUP: The gift and the curse of this group is that it is loaded with so much athleticism that several players can play more than one position on the floor.

It makes for a somewhat position-less lineup in which guys can fill many roles at different times. That takes everyone on the court being on the same page.

“We’re asking a lot of our players to be basketball savants now, rather than just basketball players,” Irving said, adding that the Celtics are no longer a team that can simply go out and play with nothing to lose. “It’s gonna take some time for us to figure that out.”

SCARY TERRY: Rozier performed well after being thrust into a starting role during the final stretch of the regular season and playoffs with Irving injured.

Rozier goes back to the bench now as he enters a pivotal fourth season. He will be restricted free agent this summer and will likely command attention from other teams.

He said this group’s mentality is NBA finals or bust.

“Anything we did less than last year is a failure,” he said.