Joel Embiid got a much-needed night off.

The 76ers center missed Monday night’s game against the Portland Trail Blazers for rest. This off day was planned as the Sixers are in the midst of playing six games in nine days, including two sets of back-to-backs.

Embiid has also been hampered with right knee soreness since bumping knees in the Oct. 20 season opener in New Orleans. However, the Sixers stressed that rest — not the knee — is why the four-time All-Star has the night off.

“It was just planned,” coach Doc Rivers said. “This was the day we had planned. That’s as much as I know. We kind of went over the schedule. We go over it monthly, and we play it out. It doesn’t always go as planned, obviously. But so far, so good.”

He had an MRI on his right knee this weekend that revealed nothing of concern, ESPN reported. Rivers declined to confirm if Embiid, who’s expected to return Wednesday, had an MRI.

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Andre Drummond started in his place against the Blazers.

Embiid is averaging 21.0 points, 8.7 rebounds, 3.8 assists, and 1.7 blocks. He had 19 points and five rebounds in Saturday’s 122-94 victory over the Atlanta Hawks. After facing Portland, the Sixers will host the Chicago Bulls Wednesday before traveling to Detroit to face the Pistons Thursday.

They’ll conclude their two-game road trip at Chicago on Saturday. Then the Sixers will host the New York Knicks (Monday) and Milwaukee Bucks (Tuesday) in another set of backs-to-backs.

Drummond was acquired this summer to back up Embiid and start when the MVP runner-up has nights off. Drummond, a two-time All-Star, averaged 5.2 points, 9.0 rebounds, and 1.0 block.

Ben Simmons (personal reasons) and Grant Riller (left knee surgery recovery) also missed Monday’s game for the Sixers (4-2).

Simmons update

Rivers said Simmons made strides since Saturday in regard to his workouts. On Saturday, Simmons worked with the medical staff, rode the exercise bike, and did individual shooting drills.

“Same stuff,” Rivers said. “I don’t know if you call it progress. But definitely more shooting and more work today for sure. This is the most that I saw him working by far.

City Edition uniforms

The Sixers unveiled their 2021-22 Nike City Edition uniform on Monday in honor of the NBA’s 75th anniversary season.

The Sixers are paying homage to the famed Spectrum, which served as their home arena from 1967-96. The team will don the uniform in Wednesday’s game against the Bulls.

“I think it is a really, really, really dope jersey,” Drummond said. “I like the jersey a lot.”

The uniform, with a navy-blue base color, features a red, 1970s-style “Sixers” wordmark across the chest, which was inspired by a similar concept used in an arching fashion on 76ers uniforms from 1971-76. The uniform jersey has red, white and blue trim with both sides showcasing the Spectrum’s color panel with the colors of the Sixers (blue), Eagles (green), Flyers (orange), and Phillies (red).

The shorts have a custom Spectrum badge. There is a bicentennial “76″ logo on the other side and an “S” on the buckle of the shorts.

The uniforms also feature diamond Nike and NBA logos to represent the 75th anniversary season.