NEW YORK -- Three weeks ago, Knicks GM Glen Grunwald viewed Kenyon Martin as "insurance" against the declining health of ancient big men Rasheed Wallace and Marcus Camby.

As it turns out, Martin -- no spring chicken at 35 himself -- may end up being the Knicks' best insurance policy now that Amar'e Stoudemire is done for the regular season -- at least -- with right knee debridement…