Doc Rivers is cautiously excited to see how the 76ers’ season comes together.

“With a new coach and new system, I’m always concerned ... about early games,” said Rivers, who agreed to take the Sixers coaching job on Oct. 1.

“You don’t want to drop those,” he continued. “You just never feel like you’re exactly ready in this situation. But we have to be, so we will be.”

In addition to a new coaching staff, the Sixers’ roster includes only seven players from last season’s squad that finished sixth in the Eastern Conference and was swept in the first round of the playoffs.

The Sixers open the season Wednesday at home against the Washington Wizards. Then they’ll have road games on back-to-back nights against the New York Knicks (Saturday) and Cleveland Cavaliers (Sunday) before hosting the Toronto Raptors on Dec. 29.

The priority heading into the season is installing as much of their defensive system as possible. Offensively, Rivers feels the Sixers are pretty good transition-wise and off misses.

He concedes they’re not a good halfcourt offensive team.

“We will be, but we’re behind there,” Rivers said. “So like I told our guys, ‘Let’s not get in the halfcourt – let’s get stops [so] we can run and get out to play.’ The defense is where I’m focused most.”

There are only a couple of halfcourt plays the Sixers have mastered. They’ll run those more than others when in halfcourt situations. But Rivers realizes that Sixers will have to run the other plays.

“You don’t build Rome in a day, you know,” he said. “Sometimes it takes time. And you have to be willing to go through that pain, even during a regular-season game, to get where you want to go.”

Center Joel Embiid participated in Sunday’s practice after missing the trip to Indianapolis for Friday’s preseason finale. He sat out the Sixers’ 113-107 victory over the Pacers due to an illness unrelated to COVID-19.

Embiid is not scheduled to be on a minutes restriction for the opener.

On Saturday, the Sixers trimmed their roster to 17 players, including two on two-way contracts. That’s a maximum number of players teams are permitted to have at the start of the season. Of the 15 regular roster spots, four are taken up by centers -- Embiid, Dwight Howard, Tony Bradley, and Vincent Poirier.

“My guess is Joel’s going to play the most of the four,” Rivers said with a laugh. “I can tell you another thing – all four will never be on the floor together. It is what we have with our roster right now. We’re going to keep it that way.

“Dwight will be the backup and, after that, we’ll see what happens.”