Now, Hartwell is set for another challenging encounter at Ravens Stadium against a big, fast, multi-dimensional player: Jacksonville Jaguars tailback Fred Taylor.
"The name of the game is to dominate no matter what personnel they have," Hartwell said. "You definitely want to run through your tackles and get him on the ground."
Whether Lewis is able to play through a damaged shoulder, it's become apparent that the middle of the Ravens' defense is in sound hands. Through five starts, Hartwell ranks second on the team with 49 tackles, including his game-high 13 stops in a 22-20 loss to the Colts.
"Edgerton has the same type of mentality as a Ray Lewis," outside linebacker Cornell Brown said. "He has a great mentor in Ray. He's a strong tackler, a physical guy and an excellent athlete."
Heady praise considering just last season Hartwell was a staple of the special teams units, chasing down kickoffs and punts with little regard for his body. As a fourth-round pick from Western Illinois, Hartwell won the Buck Buchanan Award as Division I-AA's top defensive player.
That didn't grant Hartwell any special currency in the NFL, though. Defensive coordinator Mike Nolan noted during training camp the pedigree of a few other aggressive defenders who began their football careers as Western Illinois Leathernecks: Linebacker Bryan Cox and safety Rodney Harrison. He recognized a similar quality of hunger in the 6-foot-1, 250-pound Hartwell.
"Physically, Ed's what you're looking for," Nolan said of Hartwell, who recorded a school-record 512 tackles as a consensus All-American and Gateway Conference Defensive Player of the Year. "That's less than half the deal. It's what comes from inside that makes the difference."
The shift to the 3-4 from the 4-3 alignment created a job for Hartwell. As a natural inside linebacker, he wouldn't have had much of a role in a 4-3 set beyond backing up Lewis, who had made 63 consecutive starts before missing last week's game. Entering this season as one of seven new defensive starters, Hartwell wasn't exactly viewed as a glaring question mark. He was more of an unknown factor, an issue raised again after the defense struggled badly against Cleveland during the initial shock of Lewis' absence.
"Ed Hartwell is a microcosm of what this whole team is going to have to experience and go through," Ravens coach Brian Billick said after the Colts game. "He had a tremendous game. He embraced the challenge. He wasn't in awe of it. He wasn't afraid of it."
It's evident that Hartwell's comfort level with the defensive system has allowed him to play more freely. Hartwell didn't suffer from any apparent separation anxiety with Lewis out against the Colts. He even felt relaxed enough to celebrate demonstratively after tackling James for a loss.
"I do need to show more enthusiasm like that on the field and just have fun," Hartwell said. "Once you learn the system, then your athletic ability takes over. That's what an athlete does. He reacts."
Instead of dreading this matchup with the dangerous Taylor, who is often injured but is healthy now with 446 yards and three touchdowns, Hartwell and his teammates are looking forward to the action.
"Fred's one of the best and he might be one of the fastest," nose guard Kelly Gregg said of Taylor, who has 3,916 yards and 35 touchdowns in five abbreviated seasons.
Perusing the Ravens' game film, Jaguars quarterback Mark Brunell said he noticed No. 56 in addition to the familiar sight of Lewis' No. 52 jersey flashing across the field.
"Absolutely, a good player who plays great in that system," Brunell said of Hartwell. "It seems like he has some speed and is real aggressive. Obviously, he's picked up a lot of things from the guy next to him."