Both are felonies.
Deputies responded about 3:45 a.m. to Merriman's house in Poway, north of San Diego, after a woman called to say she was choked by the player and thrown to the ground when she tried to leave, Sheriff's Department spokesman Jan Caldwell said at a news conference.
Merriman's attorney, Todd Macaluso, disputed Tequila's story and said he's confident Merriman won't be charged by the District Attorney's Office.
"There was absolutely no wrongdoing on the part of Mr. Merriman," Macaluso told The Associated Press by phone. "He essentially was doing what was appropriate under the circumstances in trying to protect the safety of Miss Tequila. There were numerous eyewitnesses that will support his version of the events that transpired at his home."
Merriman, 25, was taken into custody and booked into the central jail at about 8:30 a.m. He was released shortly after 11 a.m.
Tequila was taken to a hospital. Her condition was not immediately available.
Caldwell said deputies determined Tequila had been drinking.
Asked if Merriman was trying to keep Tequila from driving drunk, Macaluso said: "We don't want to comment on her conduct. The bottom line is, he did everything in his power to ensure her safety. He hopes she comes forth and tells the truth."
Caldwell said she wasn't sure if Merriman had been drinking. Macaluso said witnesses he spoke with said Merriman had ordered water three or four times when his group was at a downtown San Diego club before going to his house. The attorney said none of Merriman's teammates were at his house.
Tequila, whose real name is Tila Nguyen, is best known for "A Shot at Love with Tila Tequila," which ran for two seasons on MTV. The bisexual dating show featured men and women vying for Tequila's affections. She has also modeled for Playboy and other men's magazines.
Scott E. Leemon, an attorney for Tequila, said in a statement that neither she nor her representatives would comment publicly.
Merriman didn't return two e-mails seeking comment. His agent, Tom Condon, said he hadn't heard about the arrest when contacted by The Associated Press.
There had been considerable Twitter chatter between Tequila and Merriman during the last two months. She tweeted several times about going to the Chargers' game Friday night and a party she held afterward at a downtown club, including:
- "Im the Head Cheerleader Prom Queen and (at)shawnemerriman is the Prom King! hahaha! LETS GOOO! LIGHTS OUT! SAN DIEGO I WILL SEE U TOMORROW!"
Merriman was the 12th overall pick out of Maryland in the 2005 draft, and had 39½ sacks in his first three seasons. The three-time Pro Bowl selection has been getting back into shape after missing nearly all of last season following knee surgery.
The Chargers, picked by some as Super Bowl favorites, open the regular season a week from Monday night at Oakland. Players had been off since after Friday night's exhibition finale against San Francisco. They are due back at practice on Monday.
"It's disappointing to hear about the issue involving Shawne Merriman," Chargers general manager A.J. Smith said in statement.
"We'll continue to monitor the situation and let the legal process run its course."
Smith didn't return a call seeking further comment.
Smith often speaks of signing "character" players, yet the Chargers have had their share of embarrassing off-field problems in recent seasons.
In 2006, there were seven run-ins with the law by San Diego players, including linebacker Steve Foley's shooting by an off-duty police officer who suspected him of drunken driving.
Merriman was suspended four games for testing positive for steroids in 2006, and linebacker Stephen Cooper was suspended by the NFL for the first four games of the 2008 season after testing positive for a banned stimulant.
Smith reportedly has been unhappy with Merriman's extracurricular activities, and there's been speculation the Chargers will let him leave when he's eligible to become an unrestricted free agent. Merriman has various business ventures and is enamored with the Los Angeles social scene. While on injured reserve last year he flew back and forth to Los Angeles once a week to appear on a football preview show.