PHILADELPHIA - When Eagles coach Chip Kelly and Patriots counterpart Bill Belichick established groundrules for their joint practices, they both agreed that fighting would not be tolerated.

It didn't take long for the rule to be tested.

On the third play of the 11-on-11 portion of the practice at the NovaCare Complex on Tuesday, Eagles cornerback Cary Williams went after Patriots rookie wide receiver Aaron Dobson. He grabbed Dobson by the facemask and the two exchanged shoves before being separated by teammates.

Kelly immediately ordered Williams - who is expected to be one of the Eagles' starting cornerbacks - to the sideline and replaced him with second-year cornerback Brandon Boykin.

Williams didn't leave the sideline for the rest of the practice. Dobson was also benched.

"(Patriots coach Bill Belichick) and I talked about it," Kelly said Tuesday. "We agreed that if someone got in extracurriculars they were going to be done for the day. That was one thing we agreed upon. We didn't want this to turn into a wrestling match. Both of our squads knew before it happened. If you're going to get in a skirmish, you're going to sit."

Kelly and Belichick apparently made a few other regulations prior to bringing the teams together.

For the first time since the Eagles held their first minicamp in May, there was no music blaring from the loudspeakers during the two-hour session.

"We just wanted to get practice in without dealing with any distractions," Kelly said. "I think our players are used to it, but I think when you first notice it, it can be distracting the first couple of times you're out there, and that wasn't what we wanted to get accomplished. We just wanted to go out there and practice against a really good football team."

The workout marked the first time the Eagles had practiced against another team during training camp since 1998, when then-coach Ray Rhodes arranged a scrimmage and two practices against the Buffalo Bills at Lehigh University.

The Patriots are more used to it.

"We've done (joint practices) from time to time," Belichick said Tuesday. "Last year, we did it twice with New Orleans and Tampa and this year we'll do it with Philly and Tampa.

"It's good for everybody. It's good for the young guys, it's good for the new guys and it's good for the coaches. We've been working against ourselves for quite a while now, so we sort of start to know each other. Now we'll see some new faces and some different matchups. It's a great opportunity."

The teams warmed up on separate fields for about a half hour before coming together for one-on-one drills that pitted one team's quarterbacks and wide receivers against another team's defensive backs. Over on another field, the offensive and defensive lines combined for a pass-rushing drill.

Eagles quarterbacks Michael Vick and Nick Foles took turns with the starters and both fared well. Wide receiver Riley Cooper, who returned to the team after seeking counseling, was their favorite receiver.

Patriots quarterback Tom Brady picked apart the Eagles' secondary with ease.

"It gets very competitive," Brady said after practice. "There's definitely a little different element (to the joint practices) because there's some new players and you want to go out and you want to do your best. They made some plays today and we made a few. Hopefully on Friday (during the preseason game), we will make more than them."

Extra points: Eagles backup quarterback G.J. Kinne lined up as a blocker for kickoff returner Felix Jones during a special teams drill and was flattened by Patriots safety Kanorris Davis. ... Patrick Chung replaced Nate Allen at safety with the Eagles' first-team defense. ... Vick and Foles split the reps with the starting offense.

Bumps and bruises: Jones and wide receiver Damaris Johnson left Tuesday's practice with strained hamstrings. ... Eagles running back LeSean McCoy (sore knee) practiced early, but did not participate in any live drills. ... Linebacker Connor Barwin was excused from practice because of an illness. ... Defensive tackle Antonio Dixon (strained hamstring) and tackles Jason Peters (strained hamstring), Dennis Kelly (lower back spasms) and Ed Wang (bruised shoulder) did not practice.

The Eagles and Patriots will practice together again today at 12:30 p.m. at the NovaCare Complex. They will combine for a light walkthrough on Thursday before playing a preseason game Friday at Lincoln Financial Field.

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