Reports had indicated that Payton was on track to return for the Finals but that statuses of Porter and Iguodala were more uncertain.
Payton has been sidelined since May 3 after suffering a fractured left elbow in Game 2 of the Warriors’ second-round series against Memphis.
Iguodala hasn’t played since Game 4 of Golden State’s first-round matchup with Denver on April 24 due to a left cervical disc injury in his neck. Porter has been nursing a sore left foot since Game 3 of the Western Conference Finals. All three players were listed as questionable after going through contact at practice on Wednesday.
The Celtics will have starting center Robert Williams in the lineup, Gary Washburn of the Boston Globe tweets. Also listed as questionable, Williams played only 15 minutes in Boston’s Game 7 win over Miami. He missed Game 3 of the series due to soreness in his surgically-repaired knee.