"Can you talk real quick?"
Jack was thrown off by the seriousness of the question. The two had known each other since childhood, dating back to their days in the DMV (D.C., Maryland, Virginia area).
Durant looked up to Jack, five years his elder, and the previous summer invited him to his Los Angeles home. They spent a week hanging out and working out. And yet, to Jack, something about the tone of the text just seemed, well, different. It wasn't how he and Durant typically conversed. They got on the line.
"What's Steph like?" Durant asked.
It didn't take long for Jack to connect the dots: Durant, a free agent at the time, was considering signing with the Golden State Warriors, the reigning championship runners-up, coming off a record 73-win season and looking for a boost to help them reclaim their throne from LeBron James.
The Warriors' recruitment of Durant had begun immediately after their Game 7 Finals loss to the Cleveland Cavaliers that June. Durant was intrigued but also unsure. Choosing where to sign would be the most important decision of his life. He needed more information.
Jack spent the 2012-13 season with the Warriors. He witnessed firsthand the early stages of Steph Curry's meteoric rise—Curry, while accepting his MVP award after the 2014-15 season, thanked Jack—and served as a mentor to Draymond Green.
"J-Jack was probably the first guy I called," Durant said. "Because it's different when you talk to coaches or guys that have just been around. Jarrett was on the floor with them when they started to make their turn. I knew he was someone I could trust, someone who understands the player's perspective."
Jack told Durant he loved everything about his time with the Warriors. "You're a great dude. They're a bunch of great dudes. You'd like it a lot," he said. Durant signed with Golden State and led his new team to a title the following June. He was named Finals MVP.
In late January, Jack, now a member of the New York Knicks, faced the Warriors, heavily favored to repeat as champions, for the first time since advising his friend. Prior to the game, he walked past Warriors general manager Bob Myers, who was standing on the sideline of Golden State's Oracle Arena talking with a couple of Knicks executives.
"You can blame this guy right here for everything," Myers said, pointing to Jack.
"Man, don't put that s--t on me," Jack responded. "I was just being honest."
Jack loves sprinkling metaphors into all manner of conversation. He does it, he says, "because I'm always trying to make sure I put things in terms that people can understand. So much drama in life comes from miscommunication."
So when he's asked about the most difficult part of being sidelined from January 2016 until September 2017 (minus a two-game stint with the New Orleans Pelicans) after tearing the anterior cruciate ligament—and then the meniscus—in his right knee, Jack explains the rehab process like this:
"Imagine I tell you that you have to read four books and study this and that to ace a test," he said. "You do all that…but then you get your grade back and it's like, 'Yo, how the f--k, bro, am I still getting a D?' That's what it's like.
"You tell me to do 88 leg lifts and do this and that, then I'll be back in four weeks. Then I do all that and you say, 'No, it's another four weeks,' and that happens again and again."
Jack pauses, takes a bite of his cheeseburger—and then weaves in a mixed metaphor.
"You gave me the grocery list, told me to go to the store, I get everything I'm supposed to and then it's like, 'You need surgery again.'"
Jack recalls these feelings one afternoon in January, sitting at a burger joint around the corner from his apartment in Riverdale, a quiet Bronx neighborhood at the northwest tip of the borough. Now 34, Jack eventually did ace his test. He signed a non-guaranteed deal with the Knicks in September and took over as the team's starting point guard four games into the season. He even helped the Knicks remain afloat until injuries—first to Tim Hardaway Jr. and later Kristaps Porzingis—undermined their slim playoff chances. Since then, with management electing to prioritize the evaluation of younger players, Jack has seen his minutes evaporate.
It's a strange position to be in for a veteran in his 13th NBA season—watching what are essentially meaningless games from the sideline, mentoring his eventual replacements. "I've never been in this situation before," Jack said.
It's also a situation Jack welcomes. It's not that he doesn't want to play anymore. The way he sees it, being a mentor is "actually what this business is about. That's actually what life is about. I can't play this game forever and...if you can help somebody else, why not? You feel good about it. That s--t comes back to you."
Jack catches a glimpse of a TV in the corner of the restaurant. He spends the majority of his off nights splayed out on his living room couch watching NBA games. Not flipping back and forth, though. He prefers to home in on one contest at a time, an East Coast game, and then a West Coast game, preferably one featuring the schematic genius of either Rick Carlisle's Mavericks or Gregg Popovich's Spurs. That way, he says, he can better notice intricate details only trained minds such as his can detect.
He follows the league closely. His attention is grabbed by a group of ESPN talking heads discussing the New Orleans Pelicans' future now that DeMarcus Cousins, one of their two All-Star big men, is out for the season with a torn Achilles. "I called DeMarcus and expressed to him how sad I was to see him go down," Jack said. "I told him I was proud of how I thought he helped turn that team around."
Jack spent fewer than 10 days as a teammate of the 27-year-old Cousins, yet somehow the two managed to form a bond. Worth noting: Cousins isn't exactly known for his genial nature. Also worth noting: The Knicks are Jack's eighth NBA team, meaning he's had more than 100 teammates. Jack seems to know everyone in and around the NBA.
"Like, you go over to his house and 2 Chainz will be there, and it's like, 'Bro, who the f--k are you?'" said Jack's longtime friend and current Knicks teammate Michael Beasley, a fellow native of the DMV. Beasley's far from the only NBA player with this sort of story about Jack.
"You can't find many people that Jack don't know. Everybody loves him," said Draymond Green, who still considers Jack a close friend and is quick to point out that he purchased his first car, a Range Rover, because Jack drove one.
Nets forward DeMarre Carroll said Jack once invited him over to his Atlanta home for a Floyd Mayweather bout. He showed up and "everyone from the NBA was there." Added Beasley: "It doesn't just extend to the NBA. Football players call him. Rappers call him, and not just calling him, they're like, 'Yo, I'm gonna be in town next month, what you doing?'"
Beasley's asked if he has a theory behind all this, an answer to the question why before and after Knicks games there's always a line of opposing players and coaches waiting to greet Jack. He proposes all the reasons you'd expect—that Jack is "genuine" and "good-hearted" and "giving." But then he shrugs his shoulders.
"Man," he said, "I've been trying to figure that out for years."
Jack spent three years at Georgia Tech before the Denver Nuggets drafted him 22nd overall in 2005. Denver traded him on draft night to the Portland Trail Blazers, with whom Jack spent his first three NBA seasons, the most time he's spent with a single team.
He learned many things in Portland, chief among them a lesson that would eventually transform him into the NBA's unofficial Prom King. During his rookie year, he was advised—he won't say by whom—to steer clear of Zach Randolph, Portland's star big man who by then had developed a reputation as one of the faces of the infamous Jail Blazers squads. On the surface, the advice made sense. There was just one issue: Jack quickly discovered that he really liked Randolph.
"Zach is one of the best dudes I've met in this whole business," he said. Also, it didn't take long for him to learn, just like the rest of the league has over the past decade-plus, that there was more to Randolph than just the ugly headlines occasionally flashing across TV screens.
"That was, like, refreshing for me," Jack says. "I could be around people and they'd be like, 'Man, he's like this and that,' and I'd say, 'No, dude, he ain't really like that.'"
It's a lesson Jack has since carried with him every day.
Green and Clippers guard Lou Williams say their favorite memories of time spent with Jack are not fit for print. The dude's clearly a fun hang. But being widely liked and widely admired are two different things.
It takes personality to be the former, but it takes something deeper—one of those magical mixes of empathy, curiosity and intelligence—to be the latter. That second trait is harder to come by, which is exactly why Jack, never an All-Star or viewed as one of the game's top guns, is considered a confidant by so many of his colleagues. "I don't even know, man; I just vibe with dudes, I guess," Jack said when asked why everyone feels so comfortable around him.
Is that really all it is?
"Maybe it's because I like to find out about people for myself."