"I feel like up until this point in my career, I've accomplished things, but ultimately, you want to get to a Super Bowl, and you want to win it," Mack said in his first training camp news conference. "And that's the only thing on my mind at this point in my career."
Despite being one of the best outside linebackers since he entered the league in 2014, team success had evaded Mack. When he joined the Chargers, Mack had played in just three playoff games over his first eight seasons, losing all.
But with the Chargers, it seemed that Mack's fortunes would shift. On paper, the Bolts would be the best team that Mack had played with in his career: Joey Bosa, Derwin James Jr. and J.C. Jackson on defense. Justin Herbert, Keenan Allen and Austin Ekeler on offense. Mack was also reunited with Chargers coach Brandon Staley, who was his position coach in Chicago.
"It was weird to hear," Mack said then of being traded, "but having a relationship with Coach Staley, it went from bittersweet to excited."
But over a year later, Mack has been part of a historic playoff meltdown and is playing for one of the league's worst teams. The Chargers (4-7) are last in the AFC West, with a 12% chance of making the playoffs.
"It's definitely frustrating, man," said Mack, gazing down at the ground after Thursday's practice. "Just understanding what we had the chance to do. You don't get too many opportunities in this league, and we're running out of them."
Mack was referring to the Chargers' most recent close-but-not-good-enough loss, which has been the theme of this Chargers team. Five of their seven losses this year have been decided by one score. Sunday's loss came against the Baltimore Ravens, the AFC's top seed.
The Chargers lost 20-10 in one of the defense's better performances of the season, limiting the Ravens' offense, which had scored 30 in their past five games, to just 20 points and 164 yards passing, their third-lowest point total all year.
With 2:57 remaining in the game, the Chargers' offense took the field down 13-10, the fifth time this season they have been in that position, but they didn't capitalize. The Ravens scored on the next drive to put the game away.
"In a game like that where it's low-scoring, where it turns into a defensive game, you have to get one more stop," Staley said after the game. "That's what we needed to do at the end of the game was just get one more stop, give Justin one more opportunity, and we weren't able to do it."
Mack has been a bright spot on the struggling defense. He sacked Jackson twice in the loss to bring his total this season to 13 through 11 games, the second most he has had in his career and his most since 2015. Mack is now only 2.5 sacks away from 100 for his career, a feat only six active players have eclipsed.
Still, Mack tried his hardest Thursday to avoid questions about the year he's having.
"Stats, whatever comes with it, it comes with it," Mack said. "But I want to win ballgames. I'm at that stage of my career where I want to f---ing win."
The Chargers will play the (2-7) Patriots on Sunday, the first step, they hope, in turning this season around after a three-game losing streak.
"We are not thinking about defeat ..." Mack said of the state of this season, "just putting one foot in front of the other. Getting ready for the next game is all you can do at this point."