CAMDEN, N.J. — The Boston Celtics and Philadelphia 76ers have agreed in principle to swap the Nos. 1 and 3 picks in Thursday’s NBA draft, and Philadelphia will use the top pick to take Washington guard Markelle Fultz, sources told ESPN’s Marc Spears, confirming news that was first reported by TNT’s David Aldridge.

The trade will be finalized on Monday. The Celtics will receive a package of picks that includes the Sixers’ No. 3 overall pick this year, sources said.

Fultz worked out for the 76ers on Saturday, a day after ESPN reported that the teams were in serious talks to swap their picks.

Fultz, donning a Philadelphia cap as he arrived at the team’s practice facility, visited the 76ers in a hastily arranged get-to-know-you session, with the workout and a meeting with team officials on his itinerary. His visit was expected to be one of the final hurdles to clear before Boston and Philadelphia could decide to actually consummate the trade.

Fultz said he was trying not to pay much attention to the trade talk.

“I’m truly blessed to be in this position,” Fultz said. “Whatever happens, I’m looking forward to taking my talents to wherever I go.”

Once the trade is finalized, the first four spots in the draft order will exactly mirror the first-four order from last year: Philadelphia would have the No. 1 pick; the Los Angeles Lakers would choose No. 2; Boston would go No. 3; and the Phoenix Suns would select fourth.

Fultz’s rise to stardom has been rapid. In 2014, he was playing junior varsity basketball in high school. Barely three years later, he’s almost certainly going to become the NBA’s No. 1 pick. And if he gets to start his pro career by calling Philadelphia his new home, he’ll be living roughly a 2½-hour drive from his hometown of Upper Marlboro, Maryland.

“I’m going to do whatever it takes to help any team I go to,” Fultz said.

The 6-foot-4 guard averaged 23.2 points, 5.7 rebounds and 5.9 assists in 25 games during his lone college season at Washington, excelling on a team that finished 9-22 and lost its final 13 games. Fultz led the Pac-12 in scoring and finished No. 6 among all Division I players, and he was the top freshman scorer in the country.

Over the past 10 seasons, only two other freshmen had a better scoring average in college: Kevin Durant for Texas in 2006-07; and Michael Beasley for Kansas State in 2007-08.

Durant and Beasley were both No. 2 picks.

Fultz might be a few days away from going one spot better.

“I just wake up and go where they tell me to go,” Fultz said.

Philadelphia had the No. 1 draft spot on three previous occasions, taking Doug Collins in 1973, Allen Iverson in 1996 and Ben Simmons a year ago.

The 76ers have a top-three pick for the fourth straight year: No. 3 Joel Embiid in 2014; No. 3 Jahlil Okafor in 2015; and Simmons in 2016. But with Fultz, Philadelphia — which has asked its fans to endure some very dismal stretches and “Trust The Process” for the past few years — would likely expect to turn a real corner toward respectability again.

Philadelphia went 28-54 this past season, after winning 19, 18 and 10 games in the previous three seasons.

Last season’s improved win total came with Okafor (50), Embiid (31) and Simmons (0) combining for 81 appearances, as Philadelphia’s trend of being absolutely snakebit by injuries continued.

However, Embiid and Dario Saric will finish in the top three when the NBA Rookie of the Year results are announced on June 26, and Simmons is expected to be ready for next season after recovering from foot surgery.