Celtics guard Kemba Walker is shown during the team's media day last month.

WHAT A DIFFERENCE a year makes for the Celtics — in terms of both roster and expectations.

If you recall, last year at this time, Kyrie Irving was coming back from an injury that cost him the playoffs from the previous season. Gordon Hayward was returning from his horrific leg injury. The depth was there. And so was the prediction the Celts would represent the East in the NBA Finals.

You might also recall that didn’t work out — and some major faces left and others came back for 2019-20.

Irving, now a Brooklyn Net, admits to the distractions that caused the Celtics to fail last season. But as we told you while last season’s drama was unfolding, guys who average 23.8 points, 6.9 assists and 5.0 rebounds per game don’t just appear out of thin air.

Kemba Walker is a fine player. Might even be the leader Irving was not.

Consider this: Irving is an NBA champion (and, yes, he won it alongside LeBron James). Irving has played in 59 playoff games. Walker has played in 11, none since 2016.

Toss in the departures of Al Horford, Marcus Morris, Terry Rozier and Aron Baynes, and you can see why the expectations aren’t what they were last year.

Checking one of the Vegas gambling sites Thursday, I saw the Celtics’ over/under for wins was 48½, eighth in the NBA and behind Milwaukee and Philadelphia in an Eastern Conference suddenly littered with ex-Celtics.

Boston would have to go 49-33 to beat that number. That’s not out of the question but certainly different from last year’s number that was some 10 wins higher (the Celtics finished last year at exactly 49-33).

For what it’s worth, ran its annual poll of the league’s general managers and the Celtics were noticeably absent.

In the poll (GMs, who picked the Clippers to win it all) couldn’t vote for their own players or team), the Celtics were picked behind Milwaukee and Philly and Jayson Tatum was tied for second in the category of a player to have a breakout season. Last year, Brad Stevens was voted the best coach, with 47 percent of the vote. This year, no votes (and I’m still wondering how he became such a lousy coach). Last year, Stevens was the coach who makes the best in-game adjustments. This year he’s No. 2 (so I guess he’s not THAT bad).

One thing is clear from what people are saying about this basketball team: Walker, Enes Kanter and Co. can use this lack of respect as a motivating factor. But don’t expect miracles out of the gate. The Celtics are opening at Philadelphia (and Horford) next Wednesday night.

Again, Hayward being further removed from that injury HAS to help — if he is completely over what happened to him.

Bombs away

The other night, rookie Carsen Edwards hit eight 3-pointers in the second quarter of a game against the Cleveland YMCA. And while making 3-pointers really doesn’t reflect on the opposition — even though it does, in terms of defense — eight treys in a quarter means something.

Column pal Larry Rosoff, who tends to exaggerate (positive and negatively) when it comes to his Boston teams, sent the following Facebook message out after the rookie’s aerial display:

“Put it down; Carsen Edwards is the next Steph Curry.”

Apologies to Jerry West, Pete Maravich and other great shooters who didn’t learn to shoot from 28 feet because there was no 3-point line, but Curry is the greatest outside shooter of all time.

Edwards made eight 3-pointers in a preseason game against the Cleveland YMCA. Impressive.

“I’ve never seen anything like that,” Stevens said after Edwards went 8-for-11 from downtown and scored 26 points in the quarter. “He was pretty special.”

The kid is only six-feet tall but Stevens says, “You look at a guy that size and you try to figure out how he does it. And he just keeps doing it.”

Edwards is opening all these eyes after lasting until the 33rd pick of the draft (the second round).

The Celtics reportedly offered Jaylen Brown a four-year/$80 million extension that was turned down. If he doesn’t sign by Monday, he will play out the season and then become a restricted free agent next offseason. Brown has an agent for the first time.

“It’s really not overwhelming me or ruling my thoughts,” Brown told the New York Times. “I know what type of talent I have. I’m confident in myself. I’m confident in my ability. It’s not something that’s keeping me up at night.”

Sleepy time

Sleep deprivation has become a problem in the NBA, understandable considering the rigors of the schedule (the Celtics open the season with three games in four nights).

“I think we live it,” Stevens said “I think that’s just part of it.”

He added: “I think it takes a real corporate desire to manage it, and then to make sure that you schedule appropriately, especially with practice times, shoot-around times, walk-through stuff at hotel, all that stuff. And then there’s an individual onus that each player, coach, support staff member has to take to make sure they maximize their sleep to the best of their ability.

“The schedule is built so that everybody can take advantage of their sleep as much as possible. You can get enough if you plan right, get everybody to use the right techniques as far as like, turn your phone off and turning the TV off and all those things. It’s doable.”

Finally, while the NBA deals with the whole China controversy, (the battle set to cost the teams plenty of money), Kanter has a battle of his own, with his native Turkey. He’s taking heat over his negative comments on President Recep Tayyip Erdogan.

In a piece in The Boston Globe, Kanter, harassed leaving a mosque, said, “Basketball is my escape. Whenever I am on the court with my teammates, either practicing or playing a game, I focus entirely on basketball. If I were to bring any of these conversations to the court, it would be very selfish of me. But as soon as I step off the court, these questions come to my mind: What can I do for innocent people in Turkey who are suffering? Am I doing enough? How can I raise awareness?

“… I have a prominent platform and I want to use it to promote respect for human rights, democracy, and personal freedom. For me, this is bigger than basketball. Being a champion of tens of thousands of voiceless people back in my home country carries a risk that includes death threats and arrest warrants.”

Kanter also tweeted he has endured the following: “Haven’t seen or talked to my family in 5 years; Jailed my dad; My siblings can’t find jobs; Revoked my passport; international arrest warrant; My family can’t leave the country; got death threats every day; Got attacked, harassed; Tried to kidnap me in Indonesia. FREEDOM IS NOT FREE”

Mike Shalin covers Boston pro sports for the New Hampshire Union Leader and Sunday News. His email address is Follow him on Twitter @mscotshay.