EL SEGUNDO — Khalil Mack doesn’t often join his Chargers teammates for practice on Wednesdays. Officially, his status is listed as NIR — Rest. As in, he wasn’t nursing an injury, but he was given an extra day to rest and recover from last week’s game and to prepare for this week’s game.

It’s nothing new for the 11-year NFL veteran.

It was a schedule developed in conjunction with former Chargers coach Brandon Staley, who wanted to make sure Mack was fresh for the next game ahead. After so many years playing the rough-and-tumble position of outside linebacker, Mack doesn’t necessarily need the practice.

What he usually needs is a break from the grind. What was new and different Friday was that Mack was listed as questionable to play Sunday for the Chargers (5-3) against the Tennessee Titans (2-6) because of a groin injury. He did not practice with his teammates Wednesday, Thursday or Friday this week.

“A couple of needles and I’ll be on my way,” he had joked after limping off the field with an injury late in the Chargers’ victory this past Sunday over the Cleveland Browns, after playing only about one-third of the defensive snaps. “I’ll be ready (to face the Titans on Sunday at SoFi Stadium).”

At least, reporters assumed Mack was joking.

It had been an eventful afternoon, after all.

Mack was credited with four tackles, including one sack of Browns quarterback Jameis Winston and two tackles for losses of yardage. He was able to play a lesser number of snaps, in part, because teammate Tuli Tuipulotu had a monster game with four tackles, including 2.5 sacks.

However, when the first injury report of the week arrived in reporters’ inboxes Wednesday, Mack was listed as having a groin injury. It was the same Thursday, too, although he spent a good chunk of time working out on the sidelines with a member of the Chargers’ athletic training staff.

Was he in serious jeopardy of sitting out a game for the first time since the Chargers acquired him from the Chicago Bears on March 10, 2022? He had played all 17 games in each of the 2022 and ‘23 seasons, earning the seventh and eighth Pro Bowl selections of his Hall of Fame-caliber career.

“I’m being close, man, I’m being close, man, I’m getting close,” Mack said Thursday. “It was a pretty good day out there, running around. I’ll come out and see how I feel (Friday). Yeah, yeah, I have to get out there early (Friday) and we’ll see from then on how it’ll go. You’ve got to take it day by day.”

Mack acknowledged that Wednesday rest days have been a key to his longevity.

“It’s added on some shelf life right there,” he said. “We came up with that when I first got here with Staley and it might have tacked on an extra five years for me right there. Those Wednesday, you know, you’ve got pads on. I don’t need that veteran bruise like when I was younger.

“It’s definitely worked in my advantage.”

Wednesdays normally include a visit to the weight room for a workout with Ben Herbert, the Chargers’ director of player performance. Mack doesn’t put on his helmet and pads, but that doesn’t mean the day is one of pure relaxation. In fact, it could be as taxing as anything he does in practice all week.

“We get to it, man, and have some fun in the weight room and do whatever else I need to get for the day whether it’s running in the pool or whatever,” Mack said. “No, I don’t take any days off. They call it a spa day, but it’s definitely not a spa day, especially with ‘Herb’ for an hour and some change.”