Warner, a former Super Bowl MVP, has been hampered this season with a hand injury.
He broke the pinky finger on his right, or throwing, hand against Dallas Sept. 29, and missed the next five games.
He played briefly against Chicago on Nov. 18, and returned to the starting lineup for the next two games, at Washington on Nov. 24, and at Philadelphia on Dec 1.
An X-ray the day following the Eagles' game revealed a fracture of the fifth metacarpal in his right hand, located at the base of the knuckle. The fracture is unrelated to the pinky injury.
Warner appeared in seven games this season with six starts. He completed 144-of-220 passes for 1,431 yards, with three touchdown passes and 11 interceptions for a passer rating of 67.4.
"I would like to play, but if you look at the situation, it is probably the best thing," Warner said. "You never want to be in a situation where you know you are not going to play the rest of the year and have to sit out. I want to get healthy and be able to do the things I am capable of doing, so this probably gives me the best chance to do that as quickly as possible."
Warner holds many team passing records including career 300-yard passing games (29), career completion percentage (66.7), highest passer rating in a season (109.2, 1999), completions in a season (375, 2001), yards gained in a season (4,830, 2001), most touchdown passes in a season (41, 1999), and most consecutive 300-yard passing games (six, 2000).
Warner became the Rams' starting quarterback in 1999. He is a two-time NFL MVP (1999, 2001) and a Super Bowl MVP (XXXIV).
Warner is the NFL's all-time leading passer with a 98.2 quarterback rating, and has passed for 14,082 yards and 101 touchdowns.
"I would have loved to have played again before the end of the year," Warner said. "In the back of my mind I was believing that there was an outside chance that I could. Now, I just have to look at it like best case scenario to get healed and to get healed as quickly as possible, and be able to start working and getting ready for next year."
He will be replaced on the active roster by wide receiver Dane Looker, who played for the Berlin Thunder in the spring.
He has been on the Rams practice squad for the entire season after being released following training camp.