For most of the past four years, JR Smith has held one of the best positions in basketball. 

As a starter placed between Kyrie Irving and LeBron James, Smith's simplified role allowed him to feast on open three-pointers and play some of the best defense of his 14-year career. He was the starting shooting guard on four straight Finals trips for the Cleveland Cavaliers, and his big third quarter in Game 7 helped deliver the franchise's first championship in 2016.

Now, with James and Irving both gone via free agency and trade, respectively, Smith is one of four players to remain from that title team just two years ago.

While the faces around him have changed, so has Smith's role for the first time since his trade to Cleveland in January 2015. On a team not even expected to reach the playoffs despite playing in the feeble Eastern Conference, Smith is suddenly in danger of falling out of the rotation altogether.

"Being in the situation I've been in for the past four years, being a starter on four Finals teams," Smith tells Bleacher Report, "it's been obviously different."

Smith's responsibilities have gone from burying laser passes from James and Irving to sharing nutritional habits with 19-year-old rookie Collin Sexton. He's treated fellow teammates Cedi Osman and Jordan Clarkson to Cleveland Browns games, all while balancing soccer practice, trips to the Lego store and first steps with his four daughters at home.

At 33, much has changed in JR's life, mostly for the better. While the idea of being a mentor may have seemed preposterous just a few years ago, Smith has embraced his new role in Cleveland.

"It's been fun," Smith says. "I've been out a lot of training camp [with a hip injury], so it makes it easier because I get to give my insight from a watching standpoint opposed to being out there, trying to play and teach on the job."

Sexton, the Cavaliers' prized rookie and No. 8 overall pick in the 2018 draft, has especially taken to Smith's guidance.

"He's been really cool. I feel like I can lean on him, ask him pretty much anything on the court as well as off the court," Sexton tells B/R. "You can tell that he's become more of a leader because there's a lot of young guys, and I feel like he's filling those shoes real well. [We talk about] game-flow stuff, what he thought about this play, or what I should have done better."

"JR's not afraid to say anything," Sexton adds. "He's going to give it to you straight."

Smith isn't the only veteran voice in Cleveland's locker room. Kevin Love is set to become the team's on-court leader after years in a supporting role. Channing Frye and Tristan Thompson are the only other members of the Cavaliers' 2016 title team that now seems like a distant memory.

"Between Kevin and myself and Tristan and JR, we're the last of the Mohicans," Frye tells B/R.

With James now in Los Angeles and previous locker room mentors James Jones, Mike Miller and Richard Jefferson all enjoying retirement, Smith's voice is more important than ever. It would have been human nature to question his mindset coming into the year, given how last season ended.

"I think JR's been through a lot," Frye says softly, instantly conjuring memories of Smith's now-infamous mental lapse in Game 1 of the Finals and the backlash that followed.

"I think he knows that we're behind him and that we see he's been working. He came into camp in great shape. He's been part of the team. As far as I see, he's bought into the new schemes and what's going on. I'm pretty proud of him."

While the camel's back may have finally broke at the end of Game 1, the entire previous season was anything but easy for Smith.

He was immediately benched following the Cavs' signing of 12-time All-Star and James BFF Dwyane Wade. After later regaining his starting job, Smith was then sent to the bench in a March lineup shuffling in favor of Kyle Korver.

Cleveland was caught between contending for a championship with James and trying to build a Plan B with its younger wings behind him should he leave in free agency. This left Smith searching for his place, bouncing between first and second units while averaging his lowest point total (8.3 per game) since 2005-06.

This year's role appears more defined. Rodney Hood has taken over as the starting shooting guard, while fellow guards Clarkson, Korver and former Chicago Bull David Nwaba look for minutes as well. According to The Athletic's Joe Vardon, the Cavs' front office told Smith's circle this summer that playing time may be tight and that they prefer head coach Tyronn Lue to go with younger players.

Any questions about how this would affect Smith's behavior or leadership can safely be put to rest.

"I think he's been awesome. He's been very vocal; he's a vocal leader," Frye adds. "We're just trying to establish a great culture here where guys know, 'Hey, we just want you to be your best self.' We need to develop our young guys and get out there and give them time. We've also got to keep it real, and I think that's what JR does. He definitely keeps it real, and we appreciate it."

Ask Smith why it's important for him to assume this previously foreign role, and he quickly reflects on the beginning of his own career.

Like Sexton, Smith entered the league at 19. Unlike Sexton, he made the jump straight from high school with no college to soften the blow from childhood to adult life. In those first few seasons with the New Orleans Hornets and Denver Nuggets, Smith relied upon a collection of veterans for guidance on adjusting to life in the league.

"I was the youngest guy on my team for like six years," Smith says. "I had a lot of time to soak in a lot of communication from those guys."

From his rookie and sophomore seasons, Smith lists Baron Davis, PJ Brown, Darrell Armstrong, David Wesley and Rodney Rogers as those he would go to for advice. When he was traded to Denver at age 21, he leaned on Marcus Camby and Andre Miller.

It's these memories and the experience of his 15 years in the league that's created a sense of responsibility to look after teammates like Sexton, Osman, Clarkson and others.

"More than anything, don't try to overthink the game. You're all here for a reason. You've got tremendous talent; now go out and put that talent on display," Smith says his most important message is for the young Cavs. "Have fun with the game still. Enjoy learning, enjoy the process of getting better. That's what PJ Brown really tried to install in me, because some of the guys make it to this level and are content with just making it to the league."

As for life outside the rotation? Smith is prepared for it, if need be. He's watched others do it for years now without complaint.

"Having guys come in and out like Mike Miller and JJ [James Jones], those guys really helped me from an understanding standpoint about guys who weren't playing, didn't have any intentions on playing, how they can have a huge impact on the team. Having those guys around makes it easier for me," Smith says.

It's unlikely Smith will regain his starting role with the Cavaliers. With only a partially guaranteed contract for next season, his time with the team where he won his only championship may be coming to an end as well.

"Veteran mentor" may be the final act of Smith's Cleveland career, and it's one he's ready to embrace.

Greg Swartz covers the NBA for Bleacher Report.