The NFL’s tightest division is already being rocked by injury news with training camps set to open later this week and next.

Los Angeles Chargers wide receiver Mike Williams has been placed on the Physically Unable to Perform (PUP) list with an undisclosed injury.

The No. 7 pick of the 2017 NFL Draft is eligible to come off that list at any point during training camp, which opens Thursday.

However, if he is still on the PUP list when the season starts, Williams will be required to miss at least the first four games of the season, if not more. Starting in Week 5, teams have five-week window to return PUP-listed players to practice. Those who remain on the PUP list after Week 10 will be out for the remainder of the season.

Williams, 31, returned to the Chargers on a one-year, $3 million deal this season after spending last year with the New York Jets and Pittsburgh Steelers. And although he’s no longer a threat to break the 1,000-yard mark, as he did in 2019 and 2021, Williams was expected to start along fellow receivers Ladd McConkey and Quentin Johnson this season.

And in a division that includes three playoff teams from last season as well as a revamped Las Vegas Raiders roster with new quarterback Geno Smith and rookie running back Ashton Jeanty, the Chargers need every weapon at their disposal.

While the Chargers held opponents to a league-low 17.7 points a game last year, Coach Jim Harbaugh & Co. ranked just 20th in offensive yards despite another strong season for quarterback Justin Herbert.

To improve the team’s 17th-ranked running game, the Chargers brought in former Pittsburgh Steelers running back Najee Harris, who avoided PUP after suffering an eye injury in a fireworks accident, and former Philadelphia Eagles right guard Mekhi Becton. Los Angeles also drafted North Carolina running back Omarion Hampton, who should provide depth if he doesn’t compete with Harris for the starting job.

Another rookie, wide receiver Tre Harris, is already holding out from training camp over a dispute about guarantees in his rookie contract.

Harris, a former Ole Miss standout, is one of 30 second-round picks who remains unsigned over the issue, which arose after Houston Texans rookie receiver Jayden Higgins signed a fully guaranteed contract in May. Higgins is the only second-round pick in NFL history to get a fully guaranteed rookie contract.

The 55th overall pick, Harris had 60 catches for 1,030 yards and seven touchdowns at Ole Miss last season after starting his college career at Louisiana Tech.