Sometimes, good teams find impact players through superior scouting and tireless research. Other times, they find them by accident.

Ravens linebacker Dannell Ellerbe might be a case of the two instances converging.

It's certainly true that the Ravens liked what they saw in Ellerbe, a rookie linebacker from the University of Georgia who went undrafted because of injury concerns and questions about his attitude and work ethic during his career with the Bulldogs. He was the only undrafted rookie the Ravens kept this year because the team saw potential in the 6-foot-1, 245-pound player. He was physical, aggressive and good at plugging holes against the run.

But it's probably a stretch to say the Ravens knew he could make this kind of impact this soon. He was, after all, behind Jameel McClain and Prescott Burgess on the depth chart for much of the year and got to play regularly only because Tavares Gooden kept missing time with injuries.

Yet there Ellerbe was on Sunday against the Oakland Raiders, making two of the biggest defensive plays this season - an interception of quarterback JaMarcus Russell, and the recovery of a fumble caused by Antwan Barnes that helped seal the Ravens' playoff berth.

"It's a blessing and a dream at the same time," Ellerbe said. "I came from a long way, battling injuries the last few years. Just to be healthy right now, playing beside Ray Lewis, is a dream."

It took Ellerbe some time to get healthy himself - he struggled with a knee injury early in the year - and to earn the trust of the Ravens' coaching staff, which didn't appear to be particularly thrilled with his attitude at times. Earlier this season, in one of the rare candid moments that has occurred during the brief practice period open to the media, special teams coordinator Jerry Rosburg launched into a profanity-laced tirade directed at Ellerbe and booted him out of a kickoff-coverage drill because Rosburg didn't think he was giving 100 percent effort.

"There are so many areas where he can get better, and he will get better," Ravens coach John Harbaugh said. "But for him to come up with those two plays in that game - the difference in the game was turnovers, in the end. And he made the plays. He gets a game ball. For a rookie to come in and do that, it's quite an achievement."

Ellerbe doesn't have the physical talent that Gooden does, but some of his strengths are Gooden's weaknesses, and vice versa. When the Ravens decided they couldn't afford to keep Bart Scott after last season, it was clear someone was going to have to fill his shoes. It has been a bumpy transition, but the franchise might have found half the answer in each of them.

Lewis couldn't resist gushing over Ellerbe's performance after the victory over Oakland, saying watching the Ravens' young linebackers play well makes him feel almost paternal.

"It gets no better, it gets no better, you know," Lewis said. "It's like me sitting there watching my kids, they make a play and then they come to me and say some of the most incredible things. I'll tell you, that is really what creates brotherhoods. When they make a play, I'm just so happy for them."

Ellerbe seemed almost dumbstruck when he was informed of Lewis' comments during a radio appearance Monday evening.

"That's awesome," Ellerbe said.

Although Gooden should be ready to play this week against the Patriots, it's very likely that Ellerbe will still be the starter. He's plenty familiar with the Patriots. One of his best games this season - before the Oakland game - came in the Ravens' first meeting with the Patriots, when he made six tackles playing in place of Gooden.

"It's a great challenge," Ellerbe said. "My first game back from an injury, I played against them the whole game, and it's a game we felt we should have won. It's going to be a great rematch."

In some respects, the way the Ravens had to scratch and claw their way into the playoffs is similar to the path Ellerbe has taken to get regular playing time. He has played well at times, had setbacks at others, but he might be playing his best when it matters most.

"I wouldn't have it any other way," Ellerbe said. "Anything worth having is worth fighting for. All the games we lost, they were close. That's just made us stronger for the playoffs."