Source: Chargers rookie OT Joe Alt has sprained MCL

LOS ANGELES -- Los Angeles Chargers rookie right tackle Joe Alt suffered an MCL sprain in Sunday's loss to the Pittsburgh Steelers and will likely miss Sunday's game against theKansas City Chiefs, a source told ESPN's Adam Schefter on Monday.

Alt, selected fifth overall by the Chargers in this year's draft, suffered the injury on his team's final offensive possession in the fourth quarter after Steelers defensive tackle Cameron Heyward rolled into his right leg.

Alt adds to a lengthy list of Chargers injuries from Sunday's game. In the third quarter, quarterback Justin Herbert aggravated a high right ankle sprain and left in a walking boot. Coach Jim Harbaugh said Monday that Herbert's X-rays were negative and that the team would know more about his status Sunday as the week went on. Harbaugh said he didn't regret playing Herbert with the injury.

"Warriors, you give them a shot. And that's what I wanted to do," Harbaugh said.

Outside linebacker Joey Bosa played just two snaps after aggravating a hip injury he nursed during the week, and left tackle Rashawn Slater left the game in the third quarter with a pectoral injury.

That means the Chargers could head into Sunday's game against the Chiefs without their top two tackles and a backup quarterback. The silver lining, however, is that the Chargers have a bye in Week 5, which could help players recover without missing additional games.