"It's fun energy," Thornton said. "We laugh together, we're hard on each other and we expect a lot out of each other. It keeps me young, keeps me fresh and keeps my mind fresh, which is important."
Both Labanc, 23, and Sorensen, 27, came into the season at a bit of a crossroads of their early careers. A sixth-round draft choice by San Jose in 2014, Labanc's creative offensive skills, especially on the power play, were often offset by his penchant for making mistakes in the defensive zone.
A free-agent signing in 2016, Sorensen displayed blinding speed that didn't always translate into enough offense to sustain his status on a scoring line and he really wasn't big or physical enough to fit on a fourth group. Both players were probably looking at make or break seasons.
And that's where Thornton came in.
"He really instilled a work ethic in them, he pushes them to be better every day," Sharks forward Logan Couture said. "He doesn't take one day off."
"He's got those guys working on little things, not only on the ice but off the ice, too. Getting here early, being prepared. They say you need to learn to be a pro in this league - and it's definitely true."
Playing the role as a hockey tutor, Thornton demanded Labanc and Sorensen put in hard work every single day during the regular season. That meant being the first on the ice for practices and last off. That meant a level of dedication in the weight room that took strength and conditioning to another level.
And there was the constant dialogue between the three whether it was on the ice between shifts or in a more casual setting on the plane or hotel on the road.
"As a line I think you have to work as a three-man unit," Thornton said. "As a line I think you've always got to constantly talk. You talk about playing for each other. We talk about little plays. You're always talking to constantly improve the chemistry of the line, and I think we've done a good job of that this year."
The result? Labanc posted career-high numbers in goals (17), assists (39) and points (56) while appearing in all 82 games, also for the first time in his three years in the league. He scored a goal and assists on three more when San Jose staged a miraculous comeback with four late power-play goals during a 4:01 span in Game 7 of their First Round triumph over Vegas.
But most important, Labanc earned the trust of the coaching staff and respect of his teammates as being a valuable two-way player who was no longer a liability on defense.
"Banker's come a long way this year," Thornton said. "He likes to play 5-on-5 and he's earned his minutes."
"It's awesome," Labanc said in response to playing with Jumbo. "He's been in the NHL for so many years, played with so many great players and just the experience he shares is so beneficial to me. I wouldn't want to be with any other player on our line."
Sorensen channeled all that speed into being an aggressive forechecker who could cycle and drive opponents nuts with his shifty moves. And he finally discovered a finishing touch. With only a combined six goals in 52 NHL games before the season, the native Swede set career highs in goals (17), assists (13) and points (30) while appearing in 80 games.
"He's helping and talking before every shift and he's just a big leader," Sorensen said. "You want to be like him, how he acts, how he prepares for every game and on the ice how he's setting us up and working hard.
"I'm going to look back when I'm retired and say I played with this guy," he added. "I'm trying to enjoy every moment, work hard and we do this together."
Thornton was just happy to bring out the best in Sorensen.
"Marcus found his goal-scoring touch this year," Thornton said. "He's always been a hard worker but this year he's found the back of the net, which I like to see personally."
Add Thornton's 16 goals and 51 points and that's pretty darn effective third forward group.
"I owe a lot to them, too, because they keep me young," Jumbo Joe said.
"Obviously it's difficult, he's used to playing 20 minutes a night, as he's gotten older he hasn't said a word about his minutes going down," Couture said of Thornton's professionalism. "He goes over the boards and helps the team any way he can. He's vocal on the bench. He's one of, if not, the most vocal leaders we have, everyone listens and follows his leads."
If Thornton does anything better than dish out assists it might be to deflect attention. But there's no ignoring how he's made a steady climb up the all-time leaders lists for assists, points and games played. In 2018-19, he really shot up among lofty company, passing and joining several luminary names.
Sitting 12th on the all-time games played list with a career total of 1,566, Thornton moved from 29th to 23rd place with his 47 games played in 2017-18 and from 23rd to 12th this season. Among those he passed last season include Teemu Selanne, Doug Gilmour, Rod Brind'Amour and The Great One - Wayne Gretzky.
This season he leapfrogged Phil Housley, Mike Modano, Steve Yzerman, Brendan Shanahan, Shane Doan, Johnny Bucyk, Alex Delvecchio, Jarome Iginla and Nicklas Lidstrom.
After passing Joe Sakic to move into 13th place on the all-time assist list before the season, Thornton's 35 helpers moved him into eight all-time while passing Mario Lemieux, Marcel Dionne, Gordie Howe and Yzerman.
And in terms of all-time points - where Thornton ranks 14th with 1,478 - he passed Brett Hull, Luc Robitaille, Jari Kurri, Dale Hawerchuk, Gilmour, Adam Oates and Bryan Trottier to move up six spots before this season. And with another 51 in 2018-19, Thornton passed Selanne and Stan Mikita.
"It's a weird and strange feeling," Thornton said. "These guys were my idols growing up.
"I've been lucky to play with so many great players, to be coached by so many great coaches and lucky enough to be healthy enough for so many years. Yeah, it's crazy to think I'm up there with some of those guys."
He was lucky with his health until he needed offseason surgery each of the last two years to repair torn ACL and MCL muscles in each knee. Yet those kind of injuries at his age, when NHL players are getting younger and faster every season, did nothing to deter Thornton's work ethic.
He rehabilitated each injury and was arguably the team's best forward the last two months of the regular season looking as good as new.
"The last two years have been tough, but I've worked hard to get back," Thornton said. "I'm feeling strong again, my mind is strong and hockey is a lot of fun for me right now. It's an enjoyable time in my career."
The fact Thornton loves to come to the rink and realizes he's playing a kid's game as an adult goes a long way.
"You have fun when you come to the rink, and that's the biggest thing he preaches," Couture said. "You've got to enjoy this game. There's ups and downs, there's tough times but you're playing hockey for a living and he'll constantly remind you of that."