Update: Nobody can say for sure what DeSean Jackson was thinking as he left the practice field on a cart Saturday afternoon, a forearm pressed to his face. But one thought that might have flitted through No.10's mind was the fact that he entered the first full day of workouts without that contract revision he was seeking, and now, here he is, with some sort of back injury, the Eagles said, still making just $480,000 this year.

Jackson, the Eagles' marquee receiver, was running a slant pattern Saturday afternoon, in the noncontact, no-pads session of the day, when he hauled in a Kevin Kolb pass, between Asante Samuel and Omar Gaither, then landed awkwardly on his tailbone.

Eventually, Jackson limped off the field, favoring his right leg, then rode the cart into the locker room.

 Earlier: The Eagles did their first hitting of the 2010 preseason this morning at Lehigh, a spirited session in front of an enthusiastic crowd announced at 8,328. Not in attendance were running back J.J. Arrington, acquired from Denver late Friday night, or veteran wideout Kelley Washington, most lately of the Ravens, who agreed to terms Saturday morning. The Birds released receiver Jared Perry to make room for Washington. Perry, a Missouri teammate of Jeremy Maclin's, was signed after he worked out for the Eagles earlier this week on the same day Washington did.

Arrington, 27, is expected for the afternoon session. He is an excellent pass-catching back but is coming off a year away from football while recovering from microfracture surgery, just about the most serious knee procedure for athletes, in which a surgeon drills holes to try to get the knee to grow a cartilage-like substance where there isn't any. Several NBA stars have come back from it very well, not so many NFL skill players, though New Orleans running back Reggie Bush certainly did, having undergone the procedure following the 2008 season.

An Eagles source emphasized Friday night that Arrington will have to pass a physical, or the trade becomes LB Joe Mays for a 2012 sixth-round pick. Agent J.R. Rickert said today that Arrington is healthy and will help the Eagles.

"He's a good runner," Eagles coach Andy Reid said. "He's tough, he's elusive, he's got good hands -- he's a good catcher."

Washngton turns 31 Aug. 21. He is a large, possession-type receiver (6-3, 218), who has been a good special teams player, Reid noted, while playing for the Bengals (2003-2006), the Patriots (2007-2008) and the Ravens (2009). With draftee Riley Cooper already threatening his roster spot, Hank Baskett probably didn't need to see Washington heading his way. Washington caught 34 passes last season for Baltimore, gaining 431 yards.

Meanwhile, today's morning session was spirited, with at least a couple of fights. The most entertaining erupted when Cooper, the fifth-round rookie from Florida, reacted to contact from Ellis Hobbs that Cooper felt was beyond the 5-yard limit by shoving Hobbs, who came right back at him. Cooper is 6-3, 222, Hobbs is 5-9, 195, so middle linebacker Stewart Bradley -- exercising that leadership of the D the coaches have been touting -- came flying in and blindsided Cooper, an act that brought several other players into the scrum on both sides, but it was quickly sorted out. Bradley was given a game misconduct and the offense went on a five-minute power play. (Not really, I made that part up.)

"Ellis is like, 110 pounds, so I gotta watch out for him," Bradley said later. "That’s just camp. It gets hot. You get tired. Tempers flare, and it’s fun. I don’t mind it. I’m sure everyone’s cool and shaking hands afterwards, but that’s just kinda the way it goes.”

The other combatants concurred.

"We had a little talk afterward. I gave him a little shove, and he didn’t like it. So, it’s over. We’re good,” Cooper said. I don’t go out there with that attitude. I’m an easygoing guy, man. But yeah, I’m not gonna take any crap from nobody. He’s a good dude, though. He didn’t mean anything by it. I didn’t mean anything by it, and it’s in the past ...
I don’t go out there with that attitude. I’m an easygoing guy, man. But yeah, I’m not gonna take any crap from nobody. He’s a good dude, though. He didn’t mean anything by it. I didn’t mean anything by it, and it’s in the past.”

Hobbs, a colorful talker, had more to say.

"I took his helmet off, (then) I unsnapped mine to make it fair," Hobbs said. "But I'm not all about that, man. I'm about tough football, and I'm about playing football hard, the right way. I mean, if you're going to take cheap shots, wait 'til I turn, then knock me down -- he had been doing that stuff in the previous (noncontact) practice ... just settin' a tone man ... I'm not gonna sit here and just take crap. We're going to play hard, we're going to play hard the right way."

Hobbs agreed that Cooper felt Hobbs didn't break off contact at 5 yards.

"I don't know what he's used to, but I watched his Florida films, and he's a guy that likes to pull and tug," Hobbs said. "Against LSU, he pulled a guy backwards, and (Tim) Tebow hit him on a go route. He likes to put his hands on people; when you've got guys like that, typically, they don't like to be touched. As you see, when he gets touched, he gets riled up a little bit -- Riley gets riled up.

"It is what it is. I'd rather see him do that than cower down. He did his job and I did my job ... It's over."

Reid offered his usual response -- "those things do happen, but don't make it a habit -- we're not ultimate fighters, we're football players."

Reid noted that new WIL Ernie Sims misunderstood and laid a heavy lick in one drill that wasn't live, which drew a rebuke.

"I'd rather have it that ways, where he's very aggressive; I'd much rather have it that way. It's much harder to turn 'em up," he said.

In nonpugilistic highlights, the first play of the ones vs. the ones -- the starting offense vs. the starting defense -- Bradley lurked in traffic, then popped out and picked off Kevin Kolb's pass over the middle to Jeremy Maclin. Kolb recovered on the next snap, when he hit DeSean Jackson for a long "touchdown" down the right side, though in a real game setting, Kolb would have been trying to roll away from pressure instead of staying planted.

"(Bradley) made a great interception; that was tremendous," Reid said. "He hid himself in there, kind of stuck inside. Did a nice job of reading it and hiding himself from Kevin. You won't see Kevin do too many of those. He's pretty good with that."

Kolb said: "Everybody was ready to get the pads cracking."

Michael Vick participated in a first-day training camp scrimmage for the first time since 2006 and looked pretty sharp. At one point, Vick's fellow Virginia Tech alum, DE Darryl Tapp, collided with the QB in the pocket, then threw his hands skyward to protest his innocence as Vick hit the turf.

"Pretty intense out there," Vick said. "I've never been in a training camp where the crowd was into it, it's live -- I see why these guys win year-in and year-out."

Vick didn't know who'd hit him. "That was Tapp?? We'll definitely have some words later on," he said.