LONDON – It's easy to forget that you're in the United Kingdom when entering the NBA office in the Endeavour House building on Shaftesbury Avenue.

A poster-sized NBA logo surrounded by a casing of 132 Spalding NBA basketballs greets you when you exit the elevator. That's directly in front of the Magic Johnson room, decked out in Los Angeles Lakers purple and gold and Johnson memorabilia.

The lobby's right and far back walls are decorated with pictures of 76ers and Boston Celtics standouts in front of NBA benches, a ball rack and two Gatorade coolers to promote Thursday's game between the teams. Pictures of a who's-who of international stars, including Joel Embiid, adorn the walls of the office. The place also has a mural noting all of the NBA games played internationally. There are rooms named for Michael Jordan and Larry Bird. And as to be expected, one couldn't avoid the Sixers and Celtics jerseys, warmups, socks, etc.

It's obvious the NBA's popularity is huge here in England and in Europe as a whole. How else can you explain 64 Europeans currently on NBA rosters?

That's why the league is excited about Thursday's 3 p.m. EST matchup between the Atlantic Division rivals here at The 02 Arena on the 25th anniversary of the first NBA London game: Orlando's 120-95 preseason win over Atlanta on Oct. 30, 1993.

Thursday's matchup will mark the eighth consecutive NBA London regular-season game sellout.

"It is really truly our European all-star [game]," Ben Morel, NBA senior vice president and managing director of Europe, the Middle East, and Africa, said of NBA London. "We are very happy with it, and having two well-storied NBA franchises like the Sixers and Celtics make it more appealing this year."

The Sixers are riding a four-game winning streak. At 19-19, they are off to the team's best start through 38 games since it went 22-16 in the strike-shortened 2011-12 season. The Sixers were a half-game behind the Indiana Pacers for eighth place in the Eastern Conference standings entering Monday's games. The conference's top eight teams at the conclusion of the 82-game regular season will advance to the postseason.

Meanwhile, the Celtics (33-10) have the conference's best record. They are on a six-game winning streak.

"A lot of people are coming from France and across the continent of Europe to attend that game," Morel said. "Obviously, the international talent on both teams, especially the Sixers, is key."

Second-year power forward Dario Saric is expected to have a large contingent of family members from his native Croatia in attendance. This will mark the first time Saric's father, Predrag, will see him play in person since he joined the Sixers.

Embiid (Cameroon), Ben Simmons (Australia), Timothe Luwawu-Cabarrot (France) and sidelined player Furkan Korkmaz (Turkey) will also have plenty of international fan support. There's even supposed to be a Sixers event at Kensington Palace.

They won't be the only team receiving support over here.

The Celtics are also popular in London. Folks here remember them defeating the Minnesota Timberwolves in The O2 Arena back on Oct. 10, 2007, the year the building opened. Boston went on to win the NBA title that season.

The Celtics also have their share of international players. Kyrie Irving was born in Australia. Al Horford is from the Dominican Republic. Aron Baynes (Australia), Abdel Nader (Egypt), Daniel Theis (Germany) and Guerschon Yabusele (France) are the team's other international players.

And based on what's at stake, Thursday's matchup is the most significant NBA London game to date.

"We've had some playoff races before," Morel said. "But this one in terms of having that sort of local rivalry and sort of historical rivalry is definitely a plus this year."

That's great for the NBA, which has been globally adored for some time.

The NBA objective is to continue to build the sport's fan base around the world. That involves bringing more content for its international fans.

"In Europe, especially, a lot of our games are in the middle of the night, because of the time difference," Morel said. "So we are working more closely to bring more games in an available time slot."

That's why on Sundays, there's always a televised game at 3:30 p.m. EST, which would be 8:30 p.m. in London and 9:30 p.m. in Central European Time.

That enables the league to showcase its game, develop its merchandise and promote the game globally.

"Europe is the birthplace of globalization of the NBA," Morel said.

It's hard to argue after setting foot in the league's office here.