NEW YORK -- The 76ers will be without their starting power forward and backup center Friday against the New York Knicks.

Power forward Al Horford is scheduled to miss the 7:30 p.m. game at Madison Square Garden to rest. Meanwhile, reserve center Kyle O’Quinn will miss his third consecutive game with a left calf strain.

In addition, shooting guard Josh Richardson is sidelined with right hamstring tightness. Meanwhile, Ben Simmons will play after being listed as probable with upper respiratory infection at earlier in the day. The point guard did not participate in Friday morning’s shootaround.

The Sixers called up two-way player Marial Shayok from their NBA G-League team, the Delaware Blue Coats.

With Horford and O’Quinn out, the Sixers (12-6) will be undermanned in the post against the Knicks (4-14). While O’Quinn is listed as the backup center, Horford usually slides to the center spot when starter Joel Embiid doesn’t play or comes out of the game.

Jonah Bolden, another reserve center, is assigned to the Blue Coats. That leaves two-way center Norvel Pelle and Embiid as the only available centers for Friday’s matchup. Pelle has yet to see any game action.

Horford is averaging 14.4 points, 7.2 rebounds, and 4.1 assists this season. This will mark the second game he’ll miss to rest.

Like Bolden, reserve guard Shake Milton is assigned to the Blue Coats. However, he is questionable with an upper-respiratory illness for Friday matchup against the Westchester Knicks.