ORCHARD PARK, N.Y. -- A person with direct knowledge of Josh Allen's injury tells The Associated Press the Buffalo Bills rookie quarterback has been diagnosed with a sprained right elbow on his throwing arm and is not expected to play against Indianapolis on Sunday.

The person says Allen's playing status is considered week to week as opposed to being indefinite. The person spoke to The Associated Press on Tuesday on the condition of anonymity because the team has not revealed the nature of the injury.

The first-round draft pick was hurt while being hit on both sides shortly after completing a pass in the third quarter of a 20-13 loss at Houston on Sunday.

The injury leaves Buffalo choosing between turnover-prone Nathan Peterman and newly signed veteran Derek Anderson to start Sunday.

Peterman has thrown four interceptions this season, including two in the final two minutes against Houston. The second-year player lost the starting job after faltering in a 47-3 season-opening loss at Baltimore.

Anderson is a 12-year veteran who was lured out of semiretirement to sign with Buffalo last week to mentor Allen. The 35-year-old Anderson attempted just eight passes in three appearances with Carolina last season, and hasn't started a game in nearly two years.