A year ago Thursday, LaMarcus Aldridge arrived for the first practice of his first training camp in a Spurs uniform.

He was the new guy on a team that had been together, it seemed, since before the advent of the shot clock. He had much to learn and much to do in order to fit in.

At times early on, Aldridge admits his new life felt like a whirlwind.

“I felt comfortable toward the end,” Aldridge said. “I felt like I knew where my shots were going to come from, and the team understood me and my game more. Now it should be easy for me.”

That’s good news for Aldridge, who enters his second Spurs season as the lone big man remaining from last year’s roster.

Gone is franchise cornerstone Tim Duncan, who has retired from playing and is now, in coach Gregg Popovich’s words, “coach of whatever he feels like.”

In a package deal, Boris Diaw and his espresso machine were traded to Utah.

Folk hero Boban Marjanovic is off terrorizing the rims of suburban Detroit.

David West’s late-career championship chase led him to Golden State.

Matt Bonner, at last sighting, was still working out in his native New Hampshire and hoping to latch on with an NBA team.

“We’ve had summers with this kind of turnover,” general manager R.C. Buford said after Wednesday’s practice. “But when one of them is Tim, that has a bigger impact than other summers.”

The year after Duncan retired was always going to be a major transitional season for the Spurs. Nowhere have those growing pains been felt more acutely than among the team’s new collection of big men.

Buford and Popovich managed the Duncan-sized hole in the team’s starting lineup as well as it could be managed, adding 36-year-old Pau Gasol — a six-time All-Star and two-time NBA champion — to pair with Aldridge.

Gasol won’t be what Duncan was defensively, but the Spurs can find use for the 16.5 points and 11 rebounds the 7-foot Spaniard averaged last season in Chicago.

“We were lucky to sign him,” point guard Tony Parker said of Gasol. “Losing Timmy, you can’t replace a guy like that. At least we have Pau and LaMarcus. It’s going to be a great combination.”

To round out the bench rotation, the Spurs signed free agents David Lee, a two-time All-Star who won a title in 2015 with Golden State, and Dewayne Dedmon, a fleet-footed 7-footer who spent the past 2½ seasons with Orlando.

Lee, 33, is looking for a bounce-back from a 2015-16 campaign he finished in Dallas after falling out of the rotation in Boston.

A 12-year veteran, Lee has averaged a double-double on four occasions. He is two seasons removed from putting up 18.2 points and 9.3 rebounds for the Warriors.

“I’m not coming here saying, ‘LaMarcus better watch out, I’m taking his spot,’” Lee said. “Those two guys (Aldridge and Gasol) are established All-Stars. I want to come in here and whatever minutes I’m given, I’m going to play them with energy.”

Popovich said the early returns have been positive for Lee, who dropped 15 pounds from last season’s playing weight.

“Just in these three practices, he’s been doing what we have seen him do (before),” Popovich said. “He’s a grown man. He understands how to play. He will be somebody who is important to our rotation, for sure.”

The lesser known Dedmon, 27, is among the most athletic big men the Spurs have had under Popovich.

A pick-and-roll finisher who can run the floor, Dedmon also averaged nearly 2.5 blocks per 36 minutes for the Magic last season.

“He’s a Bruce Bowen in a bigger guy’s body,” Popovich said. “We want him to play D, rebound, block shots, run the floor and keep things together in that regard. We’re not going to have 14 plays we run for him.”

When it comes to finishing his big-man puzzle, Popovich has other pieces at his disposal.

Third-year forward Kyle Anderson could see time as a versatile power forward in some lineups, a la Diaw.

Newcomer Davis Bertans — a 6-foot-10 rookie who was among the top distance shooters in Europe last season — might fill Bonner’s role as a floor-spreader.

As it was for Duncan for nearly two decades, it will be up to Aldridge to anchor the Spurs’ frontcourt on a night to night basis.

Aldridge averaged close to 20 points and nine rebounds after the All-Star break last season, as he finally found his footing in the Spurs’ offense.

“It took time for us to understand how he fits best and for him to learn how to best impact our club,” Buford said. “The continued production you saw was us all learning to play together.”

A year later, with Aldridge now the old hand, a new collection of Spurs big men are set to figure that out all over again.