Chargers' bad luck continues as offensive line injuries threaten their season ... again

The good news for the Los Angeles Chargers was that over the offseason, their offensive line was getting healthy. That was good news after injuries to both tackles affected their offense all season. They also added a good center in free agency.

The bad news was that training camp happened. And the Chargers are going to go into the season with offensive line issues again.

Center Tyler Biadasz, signed in the offseason to a three-year, $30 million deal to fix the Chargers' problems on the interior of the line, has damage to his ACL and additional injuries to his knee, and will be out indefinitely according to ESPN's Adam Schefter. He suffered the injury in a joint practice against the 49ers on Tuesday and was carted off.

So it begins for the Chargers. And that's not the only offensive line issue.

Center Tyler Biadasz of the Los Angeles Chargers suffered a knee injury in practice on Tuesday. Ric Tapia via Getty ImagesRashawn Slater dealing with knee issues

Last season, left tackle Rashawn Slater missed last season after tearing his patellar tendon in training camp, and right tackle Joe Alt missed most of the season with an ankle injury. Not surprisingly, Justin Herbert was the most pressured quarterback in the NFL last season.

Slater and Alt were supposed to return this season, but Slater's comeback hasn't been smooth. Slater suffered a "flare up" in his surgically repaired knee, via Kris Rhim of ESPN, and has been out of practice for more than a week. Chargers coach Jim Harbaugh said he expects Slater back this weekend, but the team has been a little vague on details.

Even if Slater returns soon, him missing practice is a reminder that he is coming off a serious injury and there's no guarantee that he stays healthy all season or returns at his normal level.

In a perfect world, the Chargers thought they were adding two Pro Bowl-level tackles and a center who has been in a Pro Bowl. August hasn't been perfect.

Who replaces Tyler Biadasz at center?

Even if Slater is back for Week 1, it seems like Biadasz is going to be out a long time. A rock-solid veteran center will likely be replaced by a rookie.

The Chargers drafted Florida center Jake Slaughter in the second round of the NFL Draft and it appears he's next in line at center. Slaughter had been working at guard, and if he moves to center and plays well the shift weakens one of the guard spots on the line.

The Chargers' line was an issue last season. Last season Herbert was pressured on 29.8% of his dropbacks, according to Pro Football Reference. That led the NFL. The Chargers went 11-6 despite those issues. The hope was that the offense, and Herbert in particular, would function at a much higher level with the offensive line getting both tackles back, adding Biadasz at center and having Slaughter fill a guard spot.

That plan is already being disrupted. The Chargers can't seem to catch a break.