Because he has been rehabilitating an injury, Knight isn't expected to see action in the Ravens' remaining four games and will compete for playing time next season. Knight has a history of hamstring problems.
Meanwhile, Hunter's apparent positive test this summer for ephedrine, a banned substance under the league's revised policy on anabolic steroids and related substances, will keep him out until at least Dec. 30. The sixth-round pick from Notre Dame would be eligible for the postseason if the Ravens (6-6) make the playoffs, the league said in a statement.
Ephedrine is a drug commonly found in dietary supplements that are sold over the counter at health-food stores. Published studies show it can cause seizures, strokes and, even, death.
Hunter had been playing under appeal. Ravens coach Brian Billick supports the policy, but took exception Monday with the delay from the league office on a final ruling on Hunter's status.
Hunter caught five passes for 35 yards, returning four kickoffs for a 26.3 average, including a 63-yard return against the Indianapolis Colts. Knight is a 6-foot, 202-pounder in his sixth NFL season since starring at Iowa. He turns 28 on Dec. 29.
A New Jersey native, Knight started eight games last season for the Cardinals and was a regular starter in his previous four seasons in the Valley of the Sun with 53 starts in 63 games.
Last season, Knight had 32 tackles and an interception. His best season statistically came in 1999, when he intercepted two passes with 77 tackles and 13 pass deflections.
The New England Patriots released Knight in September. Knight set the Hawkeyes' mark for interception return yards and interceptions returned for touchdowns.