LISTENING TO Chip Kelly Sunday and yesterday, it sure sounds as if it's a matter of time until rookie Earl Wolff unseats Nate Allen as a starting safety for the Eagles.

"I think Earl is growing, and we'll continue to grow him, but he's still making some mistakes out there," Kelly said yesterday, the day after pass coverage was the focal point of a 33-30 Eagles loss to the San Diego Chargers, who gained an astonishing 539 total yards. "I think they're bringing him along, and we're excited about what his future is, but we still don't feel he's ready to go the whole way."

What was striking was that Kelly didn't even pretend he wasn't awaiting the time when Wolff can replace Allen. Kelly made no attempt to defend the play of the fourth-year veteran.

Wolff played 49 of the Eagles' 83 defensive snaps Sunday. In his NFL debut 6 days earlier at Washington, he played only eight of 75 defensive snaps. Allen played 67 snaps at Washington, 63 Sunday.

"Every rep is an opportunity," Wolff said yesterday. "The more reps I get, the more confidence I get . . . If that time comes, I'll be ready for it. If not, I'll just continue to rotate."

Wolff is a fifth-round draft pick from North Carolina State, who said his biggest adjustment has been communication. Wolff said that in college, he played with the same secondary group much of his career, and was responsible for only one side of the field. He and his college teammates did things instinctively, because of their familiarity with one another.

"At this level, you have to be able to see the whole entire field," Wolff said. "I thought I tackled well [against the Chargers]. From a communications standpoint, sometimes I did good, but I feel I could get better . . . that comes with seeing the whole field. Here, every motion, every shift [changes a defensive call]. It's more of an anticipation thing in the NFL."

Corner Brandon Boykin was the rookie trying to get up to speed in last year's Eagles defense.

"It's super-tough," Boykin said, when asked about Wolff's challenge. "You're really learning on the fly . . . You're going to get criticized. You're going to have bad plays, you're going to have some good plays. You've got to keep learning, keep pushing."

Developing story lines

* The Chargers would not have converted that third-and-4 to set up the game-winning field goal — their ninth of 11 second-half third-down conversions to that point — if Eagles linebacker Connor Barwin had been able to cover the elusive Danny Woodhead. Barwin's ex-teammate, Brian Cushing, tied the Week 1 Chargers-Texans game in the fourth quarter with a pick-six on a third-down throw to Woodhead, stepping in front of the 5-8 running back. That time, Philip Rivers threw blindly toward Woodhead with a blitzer in his face. No blitzer this time, and no Eagle anywhere near Woodhead. Different play call, Barwin said. Very different defensive squad.

* Didn't notice until I rewatched the game, but Trent Cole forced that Ryan Mathews fumble after fighting through a blatant hold by former Eagles teammate King Dunlap.

* Another nugget from the rewind: The Eagles' only sack of Philip Rivers came on the Chargers' very first series. Whole lotta throwing and catching after that.

* As good as Mychal Kendricks looked Week 1, that's how bad he looked in Week 2. Antonio Gates turned him inside out, had him stumbling around in a daze.

* I counted three missed TD throws from Michael Vick to DeSean Jackson, not including the one called back on the Lane Johnson penalty. The first one, early in the second quarter, Jackson stepped out of bounds as he hauled the ball in. The second, just before halftime, Vick was hit by Dwight Freeney and couldn't make a precise throw. With 9:51 left in the third, Jackson couldn't quite reel in a slight overthrow. In each case, Jackson was behind the defense. We really could have seen one of the most astonishing receiving games in NFL history.

* The Chiefs will bring the heat Thursday, because Andy Reid knows better than anybody how dramatically Michael Vick's passing stats drop under pass-rush pressure, and because that's what Kansas City is good at, with nine sacks in two games.

* It suddenly seems relevant that Kansas City will bring back to town Quintin Demps, who has played about half the snaps so far for the 2-0 Chiefs, and is ranked 12th among NFL safeties through two weeks by Pro Football Focus. Demps was an Eagles fourth-round draftee in 2008. Earl Wolff is the highest-rated Eagles safety by PFF, at 49th. Nate Allen is 69th, Patrick Chung 77th.

Who knew?

That a coach could mess up time management at the end of a game and come out the next day and say, "That's on me," indicating that he needs to do a better job, put his players in a better position to make plays, etc. Chip Kelly kicked off Andy Reid week in style.

Obscure stat

For the second Eagles game in a row, NFL brothers will be facing off. Sunday, it was San Diego's Kwame Geathers and the Eagles' Clifton Geathers. Thursday, it's Jason Kelce and his brother, Travis, a rookie tight end for the Chiefs.

Extra point

Ken Whisenhunt, the Chargers' offensive coordinator, was the Cardinals' head coach when Bill Davis ran the Arizona defense in 2009 and 2010. You had to wonder, as Philip Rivers performed his Peyton Manningesque line-of-scrimmage wizardry Sunday, whether Rivers had slept in a Holiday Inn Express Saturday night, or whether there might be some other explanation.

Several Eagles said yesterday they didn't think Rivers really knew what Davis' Eagles defense was going to do, he just did a really good job of reading what they were presenting.

"If you look back at the film, he's just reading our coverage," DeMeco Ryans said. Ryans said he wasn't sure Whisenhunt's being familiar with Davis was a big deal. "[Rivers] made some good throws, they made some good catches. At the end of the day, we've got to defend it and get some kind of pressure, try to win at 1-on-1 matchups."

Of course, you'd think Davis would know as much about what Whisenhunt wants to do as vice versa; if so, that knowledge certainly didn't seem to help the Eagles much.


On Twitter: @LesBowen