Banks relieved David Carr in the first quarter of yesterday's win at Buffalo, completing 11 of 16 passes for 207 yards with one touchdown and one interception. His 46-yard scoring strike to wide receiver Andre Johnson was the lone touchdown in Houston's 12-10 victory.
Carr left the game with a bruised right shoulder after getting hit in the end zone by Bills linebacker Jeff Posey. The play resulted in a safety for Buffalo. Carr had an MRI in Houston Monday.
"The MRI revealed that David has a sprain of the AC joint," Capers said. "He will be out this Sunday. Tony Banks will start the game Sunday.
"We're going to have to determine how much progress he makes in the rehab."
Rookie Dave Ragone will serve as the team's backup quarterback. The Texans also signed a familiar face to the practice squad Monday, quarterback Mike Quinn. Houston also released linebacker Jimmy McClain.
"We would anticipate going into the game with two quarterbacks, unless something changes," Capers said.
Banks started the Texans' last home game, leading Houston to a 14-10 win over Carolina on Nov. 2. Carr missed that game with an ankle injury he suffered the previous week at Indianapolis. He returned to start the next two games before getting hit by Posey.
"When a quarterback has a sprain in his AC joint, it's tough for him to throw the football," Capers said. "That's why we're declaring David out this week and we'll just have to see how he responds.
"We're going to do what we think is in the best interests of David Carr.