The arrest is Foster's second in less than a month.
San Francisco 49ers linebacker Reuben Foster was arrested in California on charges related to domestic violence, The San Francisco Chronicle reports.
Foster, 23, was booked in the Santa Clara County Jail, according to the Chronicle.
Foster was arrested in January in Tuscaloosa, Ala., on a second-degree marijuana possession charge, a misdemeanor.
The NFL investigates all alleged domestic violence incidents independently. If the league determines wrongdoing, suspensions for first-time offenses typically span six games.
The linebacker started 10 games for San Franciso last season, his first in the NFL. He made 72 total tackles in 2017, the second-highest total on the team.
Foster was drafted 31st by the 49ers in 2017 after playing collegiately at Alabama.