LOS ANGELES -- The NFL on Monday suspended Los Angeles Chargers safety Derwin James Jr. for one game without pay, citing "repeated violations of playing rules intended to protect the health and safety of players, including during Sunday's game against the Pittsburgh Steelers."

James will appeal the suspension, according to a source. If the suspension is upheld, James would be eligible to return to the Chargers' active roster Sept. 30, after missing the team's Sept. 29 game against the Kansas City Chiefs.

James was flagged for unnecessary roughness for a hit to Steelers tight end Pat Freiermuth in the third quarter of Los Angeles' 20-10 loss.

In a letter to James that was included in the NFL's announcement, vice president of football operations Jon Runyan wrote that video shows James lowered his head on the hit, making illegal forcible contact with his helmet that could have been avoided.

"Your continued disregard for NFL playing rules will not be tolerated," Runyan wrote. "Substantial penalties are warranted when players violate the rules intended to protect player safety on a repeated basis, particularly when the violations carry with them a significant risk of injury to an opposing player."

James has been called for seven unnecessary roughness penalties in his career, tied with Marshon Lattimore and Jordan Poyer for second most in the NFL since 2018 (trailing Xavier Woods' eight).

However, James has racked up those penalties in fewer games than the others: Sunday was his 69th game since 2018, compared to 79 for Lattimore, 92 for Woods and Poyer's 94.

After the game Sunday, James said he was frustrated by the call and has "stopped asking" officials what he could have done differently.

"I'll look at the film and see if they sent me a fine or whatever it is," James said.

He continued, "I'm trying to get the guy to the ground. I don't feel like I hit him in the head or neck, but we'll look at it."