NOBODY KNOWS better than the Eagles that great players like Brian Dawkins don't come along every day.

Since taking the future Hall of Famer in the second round of the 1996 draft, they've selected a total of 13 safeties in the draft. Just two of those - 1999 fourth-round pick Damon Moore and 2002 second-round pick Michael Lewis - started more than 25 games for the Eagles. Only two - Lewis and '05 fourth-rounder Sean Considine - played more than three seasons with the team.

The Eagles have struggled at the safety position ever since Dawkins, who announced his retirement Monday, left for Denver after the '08 season. Despite taking safeties in the second round of the last two drafts, it still is considered a position of need heading into this week's draft, though it remains to be seen whether the Eagles agree with that assessment.

While 2010 second-round pick Nate Allen has recovered from the knee injury he suffered late in his rookie season and seems to be developing into a solid player, the other safety position still is very much in flux.

Kurt Coleman, a seventh-rounder in '10, started 13 games last season, but his play was erratic, and he seems better suited for a role as a backup and core special-teamer. Jaiquawn Jarrett, who was taken in the second round last spring, had trouble getting on the field.

Which brings us to this week's draft and the question of whether the Eagles would be willing to spend yet another high pick on a safety.

The problem this year is that even if the Eagles do want to invest in another safety, there aren't many good ones.

"It's not a good safety class," NFL Network draft analyst Mike Mayock said.

Alabama's Mark Barron is the best safety in the draft and probably will go somewhere between 10 and 15, which is where the Eagles are drafting. The only other two safeties who are expected to go in the first three rounds are Notre Dame's Harrison Smith (late first, early second) and LSU's Brandon Taylor (late second, early third).

"You're really not seeing as many safeties coming in NFL-ready as you did a few years ago," Eagles general manager Howie Roseman said. "Some of the guys that are big and fast are moving to corner [in college]. And guys that are too big are moving to linebacker. The safety position, when you're looking throughout college football, it's hard to find safeties."

As the NFL has evolved into more and more of a passing league, the role of the safety has changed. It's no longer enough to be able to stop the run and play some deep-zone coverage. With the popularity of spread formations, you've got to be able to drop down and cover slot receivers one-on-one. You've got to be big enough, strong enough and fast enough to stay with the league's ever-growing number of big, strong, fast pass-catching tight ends.

What teams are doing, particularly in lean years like this one where there are so few top-quality "true" safeties is drafting bigger corners and moving them inside to safety.

"It's a trend we're starting to see," ESPN draft analyst Todd McShay said. "There's a gray area between being a corner and a free safety in the NFL. You need guys who can match up with these bigger receivers and contend with tight ends and guys who can run down the seam. How are you going to cover a 6-6, 260-pound tight end who can run a 4.5?

"When you look at this year's cornerback class, you see a lot of big guys like [Montana's] Trumaine Johnson, who is 6-1, and [Alabama's] Dre Kirkpatrick, who is 6-1 1/2, and Josh Norman out of Coastal Carolina, who is 6-foot and change, and a lot of other guys in that 5-11 to 6-1 range. I think there are going to be a whole bunch of them that teams are going to look at and say, maybe we can move them inside [to safety]."

Mayock thinks a number of bigger corners who may lack elite speed will be drafted in the third, fourth and fifth rounds this week with the idea of moving them to safety. That group could include 5-11, 202-pound DeQuan Menzie, who played the corner opposite Kirkpatrick on Alabama's national championship team, and 6-1, 208-pound Notre Dame corner Robert Blanton.

Some others who could see their stock pushed up because of corner-to-safety projections: Jamell Fleming (5-11, 206, 4.53) of Oklahoma, Janzen Jackson (5-11, 188, 4.64) of McNeese State, and Justin Bethel (6-0, 200, 4.58) of small-school Presbyterian.

"You have to do it for a couple of reasons," Mayock said. "The league has gone to a pass-first league. So you're looking for guys who can drop down and cover the slot. You're looking for guys with more range in zone [coverage]. Secondly, because this is such a bad safety crop, it forces teams to ask, who are the corners that can move inside?"

Said Roseman: "The next level of it is maybe taking some of those corners and moving them back [to safety]."

While Roseman said the Eagles certainly would consider doing that in the later rounds, he thinks it would be a mistake to select one of the bigger projected first-round corners - Kirkpatrick or South Carolina's Stephon Gilmore - with the idea of converting them to safety. That doesn't mean the Eagles wouldn't consider drafting either of them Thursday night. It means they wouldn't do it with the idea of moving them to safety. At least not right away.

"You want to be very careful taking a projection early," he said. "Because now you're decreasing your odds of hitting on that pick. You're taking a player who has never played that position,and taking him pretty high, and now asking him to do something he's never done before."