"I have a totally different perspective," Harris said. "Coming in here as a sixth round pick I'm coming to work everyday knowing you can't half step cause you're job will get taken. It's that simple. They're looking for production and if you're not producing they're going to find somebody that looks just like you that can produce so you've got to stay on top of your game."
Harris learned that lesson early his pro career, when he took over for six-year veteran Mike Green after the first game of the season.
Despite his quick rise to a starting job, Harris didn't always know if he belonged.
The six-foot, 205-pounder played just one year of high school football and as a result received only Division on 1A scholarship offer. He was a three-time All-Sun Belt Conference performer at Louisiana Monroe, but it was his play against LSU that helped him get noticed by pro scouts.
"I remember everything about the game," Harris said. "It seemed like we played an SEC team, those were my best games. Like when we played the big schools that might be competing for a BCS bid, I had a big game.
"It was bittersweet that, individually, you could play with that level of competition. But then on the other hand you're mad because the team lost."
The fact that Harris is in just his sixth year of organized football means he's got a lot of room for growth.
"I'm still learning every week, every day, I'm still learning the position," Harris said. "If you ask half the guys in here they've been playing 15 years if you're counting back to peewee."
Being drafted was a big step for Harris, but he still had some doubts about his readiness for the NFL. However, it didn't take him long to feel at home.
"Coming from a small school you're still kind of doubtful," Harris said. "You don't know exactly where you matchup to the guys that went to Nebraska, LSU or USC. You don't know, cause the level of the competition your playing is not to that caliber. Don't get me wrong, we have good players in our conference but you look at the big schools and see what they got.
"I didn't know coming in here in training camp just practicing against each other. When we played St. Louis in the preseason. I had a pretty good game and I said to myself ‘I'm supposed to be here.' "
Even with confidence, inconsistency defined Harris' game early in the regular season. The low moment came in the 20-10 loss at Cleveland. With the Bears leading 10-6 with less than five minutes to play, Harris made a mistake in cover 2 and got beat by Antonio Bryant for a 33-yard touchdown.
The play proved to be a defining moment in Harris' season.
"I think from that point, he's really improved his play," said defensive coordinator Ron Rivera. "Also his comfort level being out there, realizing I am in the big time. I'm at the next level now."
Harris has started nine of ten games with 53 tackles, an interception, a sack and a fumble recovery to his credit. His most impressive play might have been against the Panthers.
With Carolina on the move, Jake Delhomme threw a pass to Ricky Proehl in the end zone. It looked to be a sure touchdown that would have cut the lead to 13-7, but at the last moment Harris tipped away the pass.
"It was a tremendous play because the thing about it was his awareness," Rivera said. "He realized because of their formation that Lance Briggs was put in a stressful situation and he favored Lance's side. Then they ran the post to the opposite side and he made a break from one side of the hash to the other to make the play."
Harris has gone from a long shot to make the 53-man roster to a productive member of the best defense in the NFL.