SAN DIEGO -- San Diego Chargers linebacker Thomas Keiser was arrested after a fight at a nightclub several hours after the team's victory over the Kansas City Chiefs clinched a spot in the playoffs, police said Monday night.

Keiser was taken into custody on suspicion of misdemeanor battery shortly before midnight Sunday when someone asked for a citizen's arrest, San Diego police Capt. Dino Delimitros said.

Police had been called to the restaurant and nightclub known as barleymash in the city's Gaslamp Quarter after "some sort of fight," Delimitros said.

"He got in a fight with somebody, the bouncers got involved, the police came up and somebody demanded a citizens' arrest," Delimitros said.

Delimitros said he had no further details about the incident and did not know Keiser's custody status or whether charges would be pursued.

The U-T San Diego newspaper, which first reported the arrest, said that according to jail records Keiser's bail had been set at $8,000 and he had been released by Monday night.

Keiser had one tackle in the 27-24 overtime win against the Chiefs, which completed an improbable late-season run for the Chargers and gave them the AFC's final playoff spot. They open the postseason against the Cincinnati Bengals on Sunday.

The Chargers released a statement saying they knew about the arrest, but gave no further information on Keiser's status.

"We're aware of the issue involving Thomas," the statement said. "We'll continue to monitor the situation and let the legal process run its course."

Keiser, 24, previously played for the Carolina Panthers after going undrafted out of Stanford in 2011. He began the season on the Chargers' practice squad and made the main roster in October, appearing in 12 games with 17 tackles and 4.5 sacks.