BOSTON — He was the last one off the court, his slow, structureless stride carrying him languidly toward the sideline as the clock ticked down toward an hour before the opening tip. His eyes were angled downward, yet somehow instilled with an awareness of their surroundings. Just before Markelle Fultz disappeared into the tunnel, a hand dropped down from above his head, an arm dangling from an aluminum railing like stalactite made of flesh and bone. He stopped, grabbed the Sharpie from the fan, scribbled his autograph on the 8-by-10 picture, and then, with a nod, continued on his way to the visitor's locker room.

Among the many puzzling aspects of Fultz's first year as a professional basketball player is how unfazed by it all he has seemed. On Tuesday morning, nine hours before the Sixers tipped off the 2018-19 season against the Celtics, the 20-year-old point guard leaned against the scorer's table at TD Garden and spoke as if this was just another season. A reporter wanted to know if he expected Boston's notoriously hard-edged fans — just ask Tyreek Hill — to single him out for abuse. Fultz shrugged, as if the question might have been asked of any of the Sixers, and responded, "Not really. They probably will, but I'm not really worrying about it."

Despite everything that has occurred — the headlines, the questions, the Zapruder films of his jump shot, the five-month absence from what was expected to be a consequential rookie season — Fultz has navigated the fray as if he has never really been sure what all the fuss is about. When he arrived on the outskirts of the white-encircled leprechaun at midcourt on Tuesday night, he wasn't standing anywhere that he had not expected to be. Not as far as he was concerned.

"Before the game, just hearing my name from the crowd, interacting with us, it just got my hype," Fultz said later. "It got me back feeling like basketball season is here … "

Yet this was indisputably a new chapter, a fact driven home by a halftime score sheet that showed Fultz with the second-most minutes on the team: 21 of them, behind only Ben Simmons, who had spent his first season in the NBA winning the Rookie of the Year award. What those minutes revealed is a lot more subjective in nature.

As was the case during Fultz's 13-game cameo at the end of last season, there were moments during the Sixers' 105-87 opening-night loss when you saw glimpses of the elite athletic talent that made him the consensus No. 1 pick in his draft class. In the second quarter, gliding into the lane off the dribble and rising up for a pull-up jumper, showcasing the lateral quickness that sees him cover so much ground in such a short period of time with so little effort that it is less a matter of his own speed than it is his defenders moving in slow motion against a ballhandler who isn't even trying. Later that same period, on the defensive end of the court, Fultz flicked his impossibly long arms into Al Horford's perimeter passing lane and snatched the ball like it was a horsefly that had strayed too close to the surface of a pond.

But there were other moments, too. Midway through the second quarter, the Sixers' ball movement caught the Celtics in a rotation that left Fultz open on the left wing. He was all alone as he gathered in the pass. His feet were square. His knees were bent. But instead of rising up into as good of a three-point look as they get, he seemed to hesitate, as if waiting for his defender to rotate over. It was only after the lag in the Celtics' defense disappeared that Fultz went to work, shimmying into a crossover dribble that effortlessly brought him inside 15 feet. There, he again seemed comfortable.

>> PHOTO GALLERY: Scenes from the Sixers' season-opening loss

After playing 21 minutes in the first half, Fultz logged just three in the second when coach Brett Brown leaned on T.J. McConnell and rookie Landry Shamet as the Sixers fell behind by as many as 17 and then tried to rally. The juxtaposition that was there in the playoffs had again returned, Fultz watching from the bench as Celtics second-year star Jayson Tatum finished with 23 points to tie the Sixers' Joel Embiid for the game high.

"When you look at the volume of minutes that Markelle ended up with, it's kind of where I expected," said Brown, who cited McConnell's performance against the Celtics in last year's playoff series as a factor in his decision to keep Fultz on the bench down the stretch. "He played half a game. I tried to get him a large majority of those as a point guard … As I said to everybody, and I'll say it again, Markelle is going to have steady … sometimes he is going to be just incredible, and sometimes he is going to be part of the NBA at a very young age on a pretty good team."

File Tuesday night under that second category. The final line: 24 minutes, five points, 2-of-7 shooting, a work still very much in the initial stages of progress.