Authorities confirmed that the 25-year-old San Diego Chargers linebacker was arrested on suspicion of choking and restraining Tila Nguyen, best known for her MTV dating reality show A Shot at Love with Tila Tequila.
Nguyen's condition was not immediately available.
Merriman was the 2005 AFC rookie of the year and was named to the Pro Bowl in each of his first three seasons, recording a total of 39½ sacks. He was suspended for a total of four games in 2006 after a violation of the league's steroid policy.
Merriman has been working his way back to the lineup after playing in just one game last season before requiring knee surgery.