But that's exactly what Arizona Cardinals fourth-year pro Rashad Johnson, a reserve, is doing.

Johnson had the biggest play of the game in the Cardinals' 38-10 win over the Detroit Lions Sunday at University of Phoenix Stadium. Right before halftime, Johnson intercepted a Matthew Stafford pass and returned it 53 yards for a touchdown, extending Arizona's lead to 21-7 and effectively taking the wind out of the sails of the Lions.

"Yeah, when I caught it, I pretty much knew I would score or not go back to the sidelines because I'm sure my buddies wouldn't let me get by if I was tackled one-one-one with the quarterback," Johnson told Doug and Wolf on Arizona Sports 620 Monday.

Johnson is seeing increased playing time at safety. In fact, the former Alabama standout played in a season-high 43 defensive snaps (56%) against the Lions. Johnson believes that the increased time is accelerating his development.

"This game is mental, of course, but it's also confidence," he said. "Every play that you play and every snap that you get only helps to get you more confident and what to expect in how the flow of the game goes."

Johnson's confidence is showing, as even in a limited role, he's been able to deliver several impact plays. In Week 10 against Atlanta, Johnson intercepted Matt Ryan's first pass of the game and returned it to the Falcons' 9-yard line. The play set up the Cardinals' first touchdown of the game.

He's also been a big contributor on special teams. Johnson has run the ball on two fake punts this season, picking up first downs each time and a total of 64 yards in the process. Johnson's 40-yarder against the Jets is the Cardinals' second-longest run from scrimmage this season. Despite his prowess with the ball in his hands, Johnson said he has no designs on trying to be an occasional two-way player like his teammate, cornerback Patrick Peterson.

"I definitely enjoy the opportunity to run the fake punts and the interception returns, but playing on the offensive side of the ball, you definitely have to be a special guy and Patrick's just one of those special guys that can do both," Johnson said. "For myself, getting the chances I get on punt and the opportunity to catch interceptions is what I should definitely stick to and let Patrick and those other guys who are really special do that."