Booker appeared to confirm the trade when he tweeted goodbye to Brooklyn:
Okafor, 21, was the third overall pick in the 2015 draft. He has played just 25 minutes all season, as he struggled to receive consistent playing time amid Joel Embiid's breakout. He averaged 17.5 points and 7.0 rebounds as a rookie, though he encountered multiple off-court issues that season.
Philadelphia struggled to find proper playing time for its three young centers during most of the 2016-17 season. Embiid emerged as a near-All-Star until a knee injury sidelined him from late January onward.
The Sixers shopped Okafor ahead of last season's trade deadline but found no takers. They opened the year with playoff aspirations and no role for Okafor, whose fourth-year option they declined in October. The team kept him confined to the bench, choosing shaky veteran Amir Johnson as part of their big man rotation ahead of him.
"I tried to do everything the right way. I tried to be professional; I will continue to be professional," Okafor told reporters after the Sixers declined his option. "But at some point, I have to defend myself, and this is my career. I'm not sure if [Colangelo] cares about that. I think that's evident at this point.
"But at some point, as people, on a personal level, you would hope, let's get Jah out of here. Let him go play somewhere because I'm 21. I'm healthy. I'm trying to get on the right path of my career."
The Sixers were been significantly worse with Okafor on the floor last season, per Basketball Reference. Part of that is lineup-related—most Sixers lineups without Embiid were beaten handily—but it's also a flaw that carries over from the 2015-16 campaign, when Okafor was Philly's most consistent offensive performer.
The Nets are essentially buying a look at Okafor over the next few months. He's going to be a free agent next summer, and Brooklyn is confined to offering him a maximum of what his fourth-year salary would have been for 2018-19.
"I would like for them to just send me somewhere where I can get an opportunity," Okafor told Wojnarowski in late November. "I've done everything they've asked of me, and I would just like to get an opportunity to play with a trade or a buyout. I just hope something happens quickly.
"This is my third year in the NBA, and I know it's a business. I don't know if it's fair or not, but in talking to other people in the NBA, talking to retired players, one thing I've heard them say is that what's going on with me isn't right and they've never seen anything like this before."
The Sixers will continue to build around Embiid, Ben Simmons and a strong roster of young talent.
Booker is a skilled player who can fill in some power forward minutes and provide energy off the bench. He's also an unrestricted free agent after this season, and preserving cap space is key if Philly wants to be a player on the free-agent market.