LONDON — Right now, the 76ers are an exciting basketball team.

What they aspire to be is an NBA championship-caliber team, because excitement alone doesn't even guarantee a second-round berth in the Eastern Conference playoffs.

Perhaps that's why coach Brett Brown corrected a European media member who said the Sixers and Boston Celtics bring superstar power to Thursday's NBA London game at the O2 Arena.

"We don't yet have stars," Brown said Wednesday before practice at CitySport. "We don't have any championships. We don't have any all-stars. Like, we are very much at the foundation to get to where you just brought us too quickly, in my opinion.

"I'm the coach. I have to keep it real."

The reporter was talking about Joel Embiid, who when healthy is arguably the best center in the league. The 23-year-old was third behind two forwards, Milwaukee's Giannis Antetokounmpo and Cleveland's LeBron James, in the first returns of fan voting for the NBA All-Star Game's front-court players.

"There's a difference between popular and championships," Brown said. "That's my version of a star. Are you able to get your teams to win and win championships? That's the challenge."

That's his mission for Embiid and Ben Simmons. Brown wants the Sixers to develop champions.  He'll tell you that right now they're just "scratching the surface."

The Sixers have a 19-19 record after winning four straight games. They were ninth in the conference standings heading into Wednesday night's NBA action. The conference's top eight teams at the conclusion of the 82-game regular season advance to the playoffs.

But no one can truly put a timeline on building a championship team.

So many things have to fall into place, starting with health, great draft picks and free-agent acquisitions. Brown was a part of four NBA titles during his tenure as a San Antonio Spurs assistant coach.

The Spurs had their share of standouts, led by future Hall of Famer Tim Duncan, during Brown's tenure. However, the coach said good health was the common denominator in all four titles. That let talent prevail, he said.

"It's hard to be the last man standing,"  said. "There's no generic formula to produce that. Often times, it's organic. You start moving and you retain health. But that's why we are all here."

Right now, even casual NBA followers know that health is the Sixers' biggest question mark.

Embiid has yet to be cleared to play on consecutive nights because of right foot and knee issues. He also has missed several games because of tightness in his back. In all, the center has played in only 60 games since the Sixers drafted him third overall in 2014.

Simmons is healthy now. However, the first pick of the 2016 draft missed last season with a fractured foot. Markelle Fultz, the first pick in June's draft, will miss his 35th straight game as he rehabilitates from soreness and a muscle imbalance in his right shoulder.

Fultz will watch his teammates take on a Boston squad with the conference's best record at 33-10. The Sixers lost their previous two meeting to their Atlantic Division rival this season by an average of 10½ points. However, Embiid missed the Celtics' 108-97 decision on Nov. 30 because it was the Sixers' second game on consecutive nights.

Boston forward and North Philly native Marcus Morris will not be on a minutes restriction Thursday for first time this season, the team said. Morris was recovering from a knee injury.