Garrison Mathews, like others who signed nonguaranteed deals, was told by the Knicks he’d compete for a roster spot.

“That’s what they said,” the sharpshooter nodded after Monday’s preseason game. “You know, so…”

It was appropriately an unfinished answer from Mathews, tinged with uncertainty, as the decision for the final Knicks roster spot — or spots? — rounds into the homestretch.

By Monday, the Knicks must decide who to waive among their players on nonguaranteed contracts. It’s a matter of avoiding paying salaries that count against the cap before the deadline, an imperative mission for New York as it tiptoes below the second apron.