The Philadelphia 76ers have trusted the process by building a young, potentially exciting core around Joel Embiid. (Matt Slocum/Associated Press)

Just before the start of the NBA playoffs, Washington Wizards President Ernie Grunfeld fielded questions on the successful season that was. Still, Grunfeld couldn’t help but gaze toward the future.

“We still have a very young talented core that we can continue to build with and build around,” Grunfeld said in April. “And they haven’t reached their peak yet. We’ve put the pieces together, and now they’ve shown solid, steady improvement, and they’re going to continue to improve.”

The Wizards’ future looked bright several months ago, but now there’s a vibrant glow from other parts of the East Coast that cannot be ignored.

On Monday, the Boston Celtics are expected to finalize a trade that will send the No. 1 overall pick in the upcoming draft to the Philadelphia 76ers for the No. 3 pick and other compensation. The deal crystallizes the 76ers’ young core, which will include the anticipated top pick, University of Washington point guard Markelle Fultz, along with last year’s No. 1 overall pick, Ben Simmons, and two finalists for this season’s rookie of the year award, center Joel Embiid and swingman Dario Saric.

On the other end, the asset-rich Celtics just got richer and still have enough salary cap space to add a big-name free agent this summer. This is the same Boston team that, led by all-NBA guard Isaiah Thomas, earned the top seed in the East and advanced to the conference finals.

With just one trade, the two now top the debate over which team will have the best roster in the Eastern Conference in the post-LeBron James era. The Wizards, however, remain the same talented yet flawed team they were two months ago.

“If you’re a Philly fan, you’ve got to be thrilled. These are the kinds of moves you want to see, and if you’re a Boston fan, you have to feel great as well,” said one longtime Eastern Conference scout who spoke to The Washington Post on the condition of anonymity. “How that affects [Washington]? It’s like you’re a bystander.”

In the micro view of the 2016-17 season, the Wizards should have glided optimistically into the postseason. In Coach Scott Brooks’s first year in Washington, the team rebounded from a 2-8 start to win 49 games — the greatest turnaround in NBA history.

John Wall played his way to his first all-NBA distinction. Bradley Beal lived up to the expectations of his max contract. And in his contract season, Otto Porter Jr. broke out as one of the most efficient three-point shooters in the league.

This core, which also features Markieff Morris and reserve wing Kelly Oubre Jr., consists of players 27 years old and younger. This group grappled with Boston for seven games before bowing out of the semifinals. But the core also is the dominant personality for a team that isn’t very good defensively and possesses vast imbalance.

The starters, including 33-year-old center Marcin Gortat, made up the team’s most-used lineup, and when all five played, Washington won 43 out of 69 games. But last season, as Washington drifted further from its bench, this unit logged 1,347 minutes; that was 467 more than any other five-man unit in the NBA. The Wizards’ next most-used lineup clocked in at 200 minutes.

In the playoffs, the Wizards fell in the semifinals partly because they allowed 122.5 points in the four losses.

Whereas Washington knows what it needs to do to improve, youth is the great mystery for Philadelphia. But the 76ers’ vision is coming into focus.

The 76ers enter every season with their doctors on speed dial. Simmons, 20, missed his entire rookie season with a fractured right foot, and the 23-year-old Embiid, who has provided glimpses of a payoff to all the “Trust the Process” prophecies, has played only 31 games over the past three seasons. But if health holds up, Philadelphia can begin to build a potentially exciting team.

While next season will be a transition year — as could the next two to three years — the future could look like this: Simmons on the ball, Fultz creating off it and Embiid growing into his role as the 76ers’ best player.

“I think if they do it, play well,” said another Eastern Conference scout about Philadelphia, “going into the following year then I think you could really be expecting big things from them.”

The Celtics, meanwhile, appear to value another prospect instead of Fultz to integrate into their culture and core. Even without Fultz, General Manager Danny Ainge has created a team that can win now through a series of moves in which he has emerged as the clear winner. He also is building for the future with the hope of outlasting the best player in the world, James.

As long as they have James, the Cleveland Cavaliers are the team to beat in the East. When age finally does come for the 32-year-old King, however, Boston could be in the best position to take over the conference. Along with the No. 3 pick in the deal, the Celtics also will receive a protected pick between second and fifth in the 2018 draft.

“You know [Ainge] has a plan and it’s not like a short-term plan, it’s a long-term plan, but you already have this belief in him and the choices that he’s made,” a scout said. “Instead of feeling, ‘Why the hell would we do this?’ There’s probably this undercurrent of, ‘We know that Danny knows what the [expletive] he’s doing.’ So this is probably a steal.”

Barring a stunning move this summer, the Wizards likely will return the same core. Sure, this group has yet to peak, but there’s a local downside to this week’s news: The trade between Boston and Philadelphia gives those teams more upside than what is already evident in Washington.