Mack has been a key figure on the Bolts defense in his three seasons with the team, as well as one of the more experienced members of the club.
It's why the entire team was fired up for his return, as Chargers Defensive Coordinator Jesse Minter summed up what it meant for the group.
"It means everything. He's one of the best to ever do it," Minter said. "Really, just the type of person he is, the type of leadership that he brings.
"We're super grateful he wanted to come back," Minter added. "That was really important that he wanted to be here and have another chance with this group. Just excited to have him back."
That's not even mentioning the amount he brings to the entire team as a leader.
Mack has long been lauded for his leadership presence since arriving with the squad, and his return has given the Bolts another boost in that department.
Minter spoke highly about the veteran for being in the building even before players reported for the offseason program in April, as his work ethic continues to set the tone.
"I remember — before the players got back on April 20 — I think it was early March or late February even when we started to see Khalil here on a regular basis. The work that he was putting in, the impact he had on other people to train at his level, was pretty incredible.
"For the young guys to have him around and putting in the work he's putting in and the way that he's doing it, it just makes everybody better," Minter added
The Chargers are where Mack wanted to be as he continues his journey to make it to the football mountaintop.
And both the goal and the work remains the same heading into Year 12.
"Having Heeb [Tarheeb Still] and all the other young guys around, just feeding off their energy and coming in and grinding," Mack said. "Putting my head down and grinding."
Mack later added: "I love the game of football and it's so much fun playing with these guys. That's what overtrumps all the other stuff."