With uncertainty surrounding the returns of power forwards Amar’e Stoudemire and Rasheed Wallace, coach Mike Woodson admitted he and general manager Glen Grunwald may open up a roster spot and sign a big man after the West Coast trip.

Stoudemire had his right-knee debridement surgery at the Hospital for Special Surgery yesterday and was listed as out “approximately six weeks.’’

Signing a player could mean releasing Wallace, one of Woodson’s favorites. Wallace actually is making the five-game West Coast trip, still on crutches and in a boot on his surgically repaired right foot.

Woodson admitted nothing is set in stone on Stoudemire’s playoff availability. Stoudemire returned after eight weeks when he had left-knee debridement surgery but that was to clean out a ruptured cyst. This is believes to have cleaned out loose cartilage.

There is an eight-week timetable for Wallace, who underwent foot surgery nearly two weeks ago and that’s an even bigger longshot to return.

“That’s true,’’ Woodson said of the notion Stoudemire and Wallace as no locks to be back for the playoffs.

* J.R. Smith visited with Knicks orthopedist Dr. Allen Answorth before Saturday’s game against the Jazz and is battling a sore knee but playing through it.

* Former Knick David Lee is on the verge of his first playoff berth. Sources say Lee was very disappointed in the summer of 2010 when the Knicks let him go in a sign-and-trade to sign Stoudemire.