There was a time, not too long ago, when Jarrett Jack thought his career was done. He had a torn ACL, a partially torn meniscus and, progressing into his mid-30s, the slow recovery wavered Jack's confidence.

"The rehab was easy as far as putting in the work and doing the exercises. But the doubt of, 'When I get back on the court, am I still going to be able to play? Am I doing this all for no reason?'" Jack told the Daily News. "Even when I do the exercises, man, it's still not feeling the same. Wondering physically if you'll ever get back and then after you do, mentally not allowing that to stop you."

From the initial injury with the Brooklyn Nets, it was almost two years before Jack was back playing meaningful minutes. And now he's doing it against all odds and expectations, emerging as the Knicks starting point guard despite being the only player on the roster without a guaranteed contract.

"It keeps you on your toes, forces you to stay sharp - knowing you can't take any day or any situation for granted," Jack said. "I know a lot of the owners would love to have it that way in the collective bargaining agreement."

There are many reasons the Knicks won four of their last five games heading into Sunday. The biggest is Kristaps Porzingis. But also somewhere high on the list is the decision to move Jack into the lineup to replace Ramon Sessions.