Celtics training camp opens Tuesday, and the Oct. 23 season opener against the 76ers is fast approaching. So with that in mind, here are 11 things you should know as the team tries to put last season’s sour finish in the rearview mirror.
Jaylen Brown’s extension
The Celtics have not signed a player to a rookie-scale extension since they agreed to a deal with point guard Rajon Rondo in 2009. That does not mean that they have no interest in this path; it just means that they’ve been a bit reluctant to open their coffers in these situations.
In recent years, Marcus Smart and Terry Rozier hit snags in their negotiations that could not be overcome.
Advertisement
Brown has made it through three years without an agent. His mother has handled a lot of the responsibilities, and he has worked with a marketing executive. And that was probably a savvy play on his part, as rookie contracts are locked in anyway. But these negotiations are different. One league source said it appears that Brown will retain an agent for these talks. The problem for Brown is that he has not really shown statistical improvement over his three seasons. His per-36-minute numbers are almost identical. So the Celtics will likely be reluctant to make a max extension offer. But it’s unlikely Brown would settle for much less.
The probable result is that no deal is finalized before the season begins, meaning Brown will enter next summer as a restricted free agent.
The lineups
It is no secret that the Celtics’ five best players are Kemba Walker, Jayson Tatum, Gordon Hayward, Marcus Smart, and Brown. On the court together, that group would bring versatility, playmaking, and shooting, but it does not have a center or even a traditional power forward among it, so it will be hard for coach Brad Stevens to deploy it too frequently. But there will certainly be times that he does. After that five-man unit, though, there appears to be a dip in talent.
Advertisement

Last season, Boston was almost too deep. There were so many similarly capable players that some of them seemed to thrive when there was an injury that provided some clarity about inconsistent playing time. That is unlikely to be an issue this season, but by the same token, Boston might not be able to withstand injuries as well.
The center spot
While Kyrie Irving’s departure has generated the most attention, the Celtics ultimately just replaced him with another All-Star point guard in Walker. The losses of Al Horford and defensive stalwart Aron Baynes in the middle could be more difficult to overcome.
Boston has an interesting group of big men that includes Enes Kanter, Daniel Theis, Robert Williams and Vincent Poirier. One issue with that group is that it does not include any real 3-point shooters, an increasingly essential role in today’s NBA. Theis actually made 38.8 percent of his tries last year but had just 67 total attempts. Kanter, a solid mid-range shooter, has been working diligently this summer to add the three to his game.

Williams and Poirier, meanwhile, will remain most dangerous as lob threats. The guess here is that Stevens will open the season with Kanter, a punishing rebounder, as his starting center, but will not be shy about juggling things due to matchups or progress. Kanter has been a defensive liability throughout his career, but Theis and Poirier are good defenders and Williams has elite athleticism.
Advertisement
Danny Ainge will have a close eye on the frontcourt, though, as he decides whether reinforcements are needed.
Which rookies will play?
The Celtics used four draft picks last June, selecting wing Romeo Langford (14th), forward Grant Williams (22nd), guard Carsen Edwards (33rd), and guard Tremont Waters (51st). Williams showed in summer league that he should be capable of stepping in and playing important minutes as a hard-working, bruising frontcourt player who has potential as a shooter. He will likely lead this group in minutes. Look for Edwards to eventually establish himself as an offensive sparkplug off the bench. The wing position is pretty congested for Langford, who is still just 19 years old. Waters will likely spend most of the season with the Maine Red Claws, and Langford could join him there for stretches.
Stevens glossary
We interrupt our regularly scheduled program to bring you some quick translations of things you will probably hear Stevens say pretty often in news conferences this year.
“He’s a joke.” This is the ultimate Stevens compliment for an opposing player. He generally reserves it for the best of the best.
“If we don’t play hard, we’ll get beat.” Stevens usually brings this one out when the Celtics are playing a lesser opponent that he would never identify in that fashion. Or, he might use it if the Celtics are playing a team that is missing several stars due to injury.
Advertisement
“That’s all part of it.” This is Stevens’s trademark response when media members try to give him excuses for things. For example, he might be asked about a grueling five-game road trip, or playing shorthanded. To Stevens’s credit, he never latches onto excuses.
Roster battles
In recent years, the battle for the final roster spot has sometimes been one of the most intriguing subplots of camp. Three seasons ago the matchup between James Young and R.J. Hunter went down to the wire before Hunter was waived. But it’s usually much ado about nothing, because there’s a reason these players are vying for the 15th spot in the first place. (Young had no impact that year, and his Celtics tenure came to a swift end.) Nevertheless, this is perhaps the most congested race for No. 15 in Stevens’s tenure.
Fan favorite Tacko Fall, summer league standout Javonte Green, second-round draft pick Waters, former Heat forward Yante Maten, and G league standout Kaiser Gates are expected make up the crop that tussles for the last opening. Waters might have the brightest future, but since the Celtics have already signed him to a two-way contract, they are in no danger of losing him if he doesn’t make the squad. For that reason, the guess here is that Green ultimately gets the nod. The high-flying, defensive-minded veteran has played overseas for several years. Defensive pests challenge teammates at practice more than sharpshooters do.
Advertisement
But what about Tacko!?
It almost feels like there will be a revolt if Fall does not make the Celtics’ final roster. The 7-foot-7-inch center became a sensation in Las Vegas, with fans roaring when he checked into games and booing when he was taken out. Fall, who has spent much of the summer making community service appearances for the Celtics, has been embraced by the community like few others before him.

The Celtics believe that with further development Fall could become an NBA contributor. But it’s unclear if they want to keep a development project on the roster. That’s where things become tricky. Fall signed an Exhibit 10 contract, meaning he will receive a $50,000 bonus if he is waived and agrees to then join the Maine Red Claws. But Fall’s agent, Justin Haynes has insisted that Fall will be picked up by another NBA team before that happens, and that has been reiterated to the team recently, league sources said.
New sideline faces
Stevens has had very little staff turnover since taking over six years ago, but there was some change this offseason. Micah Shrewsberry, one of the lead assistants, left to take a similar role at Purdue. The Celtics hired former WNBA standout Kara Lawson, making her the first female assistant coach in franchise history, as well as former West Virginia guard Joe Mazzulla, who has some G League coaching experience. Also, former Harvard star Allison Feaster was hired as the team’s director of player development, a newly created role.
The return
After facing the Cavaliers in his first game as a Celtic on opening night of the 2017-18 season, Irving mostly received a pass when the Celtics traveled to Cleveland. That has led many to believe he was trying to escape the wrath of Cavaliers fans, and that he could do the same when he comes back to Boston this year. But this feels a bit different. Last season Cleveland was lousy, which sapped some of the fans’ vitriol anyway and also made it easy enough for the Celtics to win without him. The Nets and the Celtics, meanwhile, are expected to battle either in the middle or toward the top of the Eastern Conference, so it seems unlikely that Irving will get a free pass. The Nets will need him. Brooklyn’s first visit to Boston comes on Nov. 27.
The other return
Oh, we shouldn’t forget about Horford. The former All-Star spurned the Celtics this summer, too, and his choice came as a much bigger surprise to team brass than Irving’s did. Horford is now a member of the 76ers, who could become the top team in the Eastern Conference. Philadelphia first comes to Boston on Dec. 12.
The new Garden
TD Garden was becoming an eyesore among all the new, state-of-the-art arenas that were popping up around the NBA. But the building has been spruced up by a $100 million expansion that added about 50,000 square feet of space around the complex. The most noticeable change, though, is that the yellow seats have been replaced by more cushy black ones.
Adam Himmelsbach can be reached at adam.himmelsbach@globe.com. Follow him on Twitter @adamhimmelsbach.