Injured reserve is the NFL's designation for players who cannot return during the current season. The Los Angeles Chargers placed starting center Tyler Biadasz on that list Sunday after the 28-year-old tore his ACL in a joint practice with the San Francisco 49ers, ending his year before a regular-season snap was played. Biadasz had signed a three-year, $30 million contract with Los Angeles this offseason after the Washington Commanders released him.

How the injury happened

The play unfolded in an 11-on-11 drill. Chargers guard Kayode Awosika threw 49ers defensive lineman Sebastian Valdez to the ground, and Valdez landed on the back of Biadasz's legs. Biadasz went down immediately and was carted off the field.

The Chargers had brought Biadasz in as an upgrade over Bradley Bozeman, who had started at center in each of Los Angeles's last two regular seasons. He was entering his seventh NFL year. His first four came with the Dallas Cowboys, who drafted him in the fourth round out of Wisconsin. His last two were with the Washington Commanders. He made the Pro Bowl in his third season with Dallas.

Who starts at center now

Second-round rookie Jake Slaughter takes over. Slaughter had been competing for the starting left guard job before the injury but played center through his college career at Florida and had already taken snaps at the position during training camp and the preseason.

This is the second straight year the Chargers have lost a starting offensive lineman before the opener. Last season, franchise left tackle Rashawn Slater tore his patellar tendon about a week after signing a four-year, $114 million contract extension. With Slater out, the team moved Joe Alt from right tackle to left tackle. Alt played only six games, limited by multiple ankle injuries.

Quarterback Justin Herbert enters this season facing the same question his line answered poorly a year ago. Biadasz was entering his seventh NFL year and held one Pro Bowl selection when he went down, not yet having played a regular-season snap for the team that paid $30 million to bring him in.