There’s been a lot of focus on how Ben Simmons’ absence impacts the 76ers offensively. However, the three-time All-Star’s refusal to report to the team has also created a notable void on the defensive end.

“It just takes one defender off the floor, and that one defender happened to be second in voting on defense,” coach Doc Rivers said of Simmons being the runner-up for defensive player of the year. “And for us, it makes us smaller.”

The 6-foot-10 Simmons was assigned to the opposing team’s best player regardless of positions one through four.

“We don’t have anyone else that can do that,” Rivers said. “That was a huge luxury.”

Now, the Sixers have to defend collectively. They might have to trap more. They might have to run around more. So Simmons’ absence has left a big hole.

The point guard, who wants to be traded, was a first-team all-defensive selection in each of the last two seasons. He led the league in steals (2.1 per game) in the 2019-20 season.

» READ MORE: Ben Simmons to Pacers? Would Malcolm Brogdon, Caris LeVert and a pick be enough for Sixers?

Reserve guard Matisse Thybulle, a second-team all-defensive selection, and small forward Danny Green are the Sixers’ best remaining perimeter defenders.

“I will say it’s going to be different with matchups, and you can’t just put me and Matisse on somebody when there’s bigger guys out there,” Green said. “We can’t have Seth [Curry] on a bigger guard, or Tyrese [Maxey] on a bigger guard, or Shake [Milton]. So we’re going to have to match up, accept that challenge.

“But it’s not just going to be on them to do that. ... You can’t replace what he did on the defensive end with one person.”

Milton goes down at practice

Milton sprained his right ankle during Sunday’s practice and will be sidelined for Monday’s preseason game against the Brooklyn Nets at the Wells Fargo Center.

He’ll become the fourth Sixer to miss a game this preseason.

Starters Joel Embiid (rest) and Tobias Harris (right knee soreness) sat out the Sixers’ preseason opener at Toronto on Oct. 4 Thybulle (right shoulder soreness) missed Thursday’s matchup vs. the Raptors.

The Sixers’ fourth and final preseason game is Friday night at Detroit. They’ll open the season Oct. 20 atNew Orleans.

Asked more specifics about Milton’s injury, Rivers said, “Honestly, I didn’t see it.”

“I actually was worried, because I didn’t see anyone around,” he added. “He went down and someone said he stepped on [Andre] Drummond’s foot. So I didn’t see it all.”

In addition to Milton and Simmons, the Sixers (1-1) will be without Harris, Thybulle, Curry (rest) and Grant Riller (right knee surgery) vs. the Nets. Brooklyn (2-0) won’t have Kyrie Irving (not with team) and Devontae Cacok (right knee rehab).

Rivers downplays rotation discussion

With Isaiah Joe added to the mix, the Sixers have 11 players with a legitimate chance to be in this season’s rotation, at least until the Simmons saga is settled.

Maxey and Milton are battling for the starting point-guard position to join Green, Harris, Embiid and Curry in a traditional lineup. Then there are reserve newcomers Drummond and Georges Niang, and backup holdovers Thybulle and Furkan Korkmaz.

“If we end up playing 11, great,” Rivers said. “If we end up playing nine, [great].”

Rivers said he’s focused on winning games over settling on a rotation. He said the lineups are going to be changeable.

“We’re not going to have a set starting lineup,” Rivers said. “Most likely, we may. We are going to change depending on who we are playing. Our players will be mature enough to handle that.”

» READ MORE: Shake Milton with starters, Georges Niang flashes versatility in Sixers scrimmage

Perhaps.

But how has Joe’s standout preseason performances influenced his thinking?

“Isaiah has been phenomenal throughout,” Rivers said of preseason games and practices. “So he’s putting pressure on people to play. That’s a good thing for us. That’s the way to look at it, because the guy who may be in front of him knows he’s coming, too.”