Chargers’ chief concern is getting off to a good start against defending AFC West champions

Trying to avoid the sort of start that had them playing uphill all of last season, the Chargers suddenly are approaching their opener with one notable hobble.

Defensive end Joey Bosa did not practice Thursday because of a foot injury suffered in early August.

Coach Anthony Lynn said “it’s possible” Bosa will be unavailable Sunday against division rival Kansas City at StubHub Center.

“Foot injuries, they take on all the weight of the body …” Lynn said. “That can be tricky, something you don’t want to rush. You want to make sure that’s right before a player comes back.”

Bosa sat out all four preseason games and spent most of training camp doing individual work in no pads. At one point, however, Lynn said he “absolutely” expected Bosa to be ready for Week 1.

On the Chargers’ initial injury report Wednesday, Bosa was designated as having taken part in practice on a limited basis. He was listed as “did not participate” for Thursday’s workout.

“Joey,” Lynn said, “he’ll be ready when he’s ready.”

If Bosa is unable to play, the Chargers would be without two of their starting defensive linemen. Tackle Corey Liuget is suspended for the first four games for violating the league’s policy on performance-enhancing substances.

Darius Philon is expected to start in Liuget’s spot, with Isaac Rochell likely to replace Bosa, if necessary.

“He got a lot of reps in the preseason and we’re pretty high where he’s at,” defensive coordinator Gus Bradley said of Rochell. “Now, Ike was going to play anyway. So I think that as a defense we feel pretty strongly about the guys that we have in place.”

The issues up front arrive at a time the Chargers are preparing to play an opponent they struggled to stop on the ground in 2017.

The Chiefs ran for 363 yards in 57 attempts in sweeping both games from the Chargers last season.

Kareem Hunt had 327 of those yards in 42 tries. As a team, Kansas City converted 17 of its 36 first downs on the ground.

This year’s Chiefs also feature a young quarterback with a strong arm and the ability to move in the pocket, but Patrick Mahomes will be making only his second career start, meaning he could be susceptible to pressure.

Early this week — before the uncertainty about Bosa’s status became public — Mahomes admitted the presence of Bosa and fellow Chargers defensive end Melvin Ingram presented “a tough task.”

Kansas City coach Andy Reid was a little more emphatic in his assessment.

“That pass rush is unbelievable,” Reid said. “It’s a nice test for our offensive line and the offense, period. You gotta make sure you really prepare and get yourself ready.”

Now, that pass rush could be compromised without Bosa, who is entering his third season and coming off his first Pro Bowl selection.

A first-round pick in 2016, Bosa has 23 sacks and 147 total tackles in 28 career games. He also has five forced fumbles, four of which came last year.

The Chargers are entering a game that feels oddly significant for being only the first of 16 during the regular season.

Not only do these two teams share the same division, but also the Chiefs are the two-time defending AFC West champions. The Chargers also have lost eight in a row to Kansas City.

A better start in 2018 seems particularly paramount given that the Chargers opened last season with four consecutive defeats and — despite 9-3 a rally — were unable to qualify for the postseason.

“A 2-2 start last year would have had us playing in January,” quarterback Philip Rivers said this week. “We know how big it is.”

Etc.

Kansas City also is facing the potential absence of one of its key defensive players. Safety Eric Berry has not participated in practice this week because of a heel injury. Like Bosa, he missed all four preseason games and has been out for about a month. … Rivers threw six interceptions against Kansas City last season. The good news? Three of them went to Marcus Peters, who is now a Ram.

jeff.miller@latimes.com