On Tuesday, Steven Marcus and Mike Rose of Newsday noted Porzingis is "off limits."
"[Knicks president] Steve Mills and [general manager] Scott Perry on the record were very clear that Kristaps was part of the future," a source told Newsday. "In all the discussions since then—there were other rumors before that Cleveland would want Kristaps—and it didn't seem that [the Knicks] were interested at all in a conversation."
The update came after Adrian Wojnarowski of ESPN.com reported earlier Tuesday the Cavs made Porzingis a "primary" target in Irving trade discussions, which have centered on young franchise cornerstones since LeBron James' future in Cleveland is unsettled beyond the 2017-18 season.
Although the 22-year-old Latvia native popped up in the rumor mill earlier in the offseason, that speculation has faded considerably since the Knicks parted ways with former team president Phil Jackson.
Porzingis expressed a desire to remain in New York for the long haul during a conversation with Shaun Powell of NBA.com before the NBA Africa Game in South Africa earlier this month.
"So far it's been tough in New York, but my journey is only beginning and I hope to stay there my whole career, so as a city we can have some fun and win some games and do something big," he said. "For me, it's now home."
If the Knicks are unwilling to include him in Irving trade talks, it will be another example of Cleveland being unable to convince other teams to insert their top young assets in the conversation.
Terry Pluto of the Cleveland Plain Dealer previously reported the Denver Nuggets would not give up Jamal Murray and Gary Harris in a possible Irving trade.
Wojnarowski listed Boston Celtics forward Jayson Tatum and Phoenix Suns forward Josh Jackson as other young players of interest if the Cavs do decide to move their star point guard.