Haynesworth, whose half-brother was killed in a motorcycle crash Thursday night in Nashville, Tenn., plans to be with his family over the next few days.
Haynesworth's agent released a statement Saturday saying the player and his family were grateful for all the support they've received.
"Regarding the tragic passing of his brother Lance McCoy, Albert Haynesworth, his mother Linda Haynesworth, and their family are thankful for the calls, e-mails, prayers and support they have received during this difficult time," the statement said.
McCoy, 23, was speeding Thursday night when he collided with a car pulling out of a parking lot. Police said a preliminary investigation found McCoy's excessive speed was the main cause of the crash.
The car's driver, Benjamin Smith, 27, of Nashville, told police he didn't see the motorcycle until impact.
A memorial motorcycle ride will be held Sunday in Nashville to honor McCoy.
Haynesworth's backup at nose tackle, Anthony Bryant, is also out with a concussion.
Rookie left tackle Trent Williams is active after being sidelined for two games with toe and knee injuries,.
The Associated Press contributed to this report.