Key areas for Patriots vs. Eagles

FOXBOROUGH, Mass. -- When the New England Patriots host the Philadelphia Eagles in preseason action Friday night, here are some key areas for the team based on what unfolded in the preseason opener:

First-unit offense together as one. Quarterback Tom Brady, left guard Logan Mankins and receivers Julian Edelman and Danny Amendola were among the key players held out of action. Furthermore, running backs Stevan Ridley (3 snaps), Shane Vereen (5) and James White (9) played sparingly. That is expected to change Friday, with a heavier focus on the running game at times.

First-unit defense together as one ... almost. Defensive ends Chandler Jones and Rob Ninkovich; linebackers Jerod Mayo, Jamie Collins and Dont'a Hightower; cornerback Darrelle Revis and safety Devin McCourty were among the top players held out of action last week. That is expected to change Friday, with everyone but Mayo looking like a lock for action. Better play against the run, and in coverage in the play-action passing game, will be a focus.

Improvement along the offensive line. Breakdowns along the offensive line were a primary contributor to the Patriots' scoreless first half against the Redskins, and it started with a holding penalty on left tackle Nate Solder on the initial third down. Marcus Cannon has been working mostly at left tackle this week in practice, and with Mankins expected to be back in the lineup, we'll see if things improve. Solder didn't finish Thursday's walk-through practice and might be dealing with some type of ailment.

Mallett's health and number of snaps. No. 2 quarterback Ryan Mallett declared he is "good to go" for action, but it will be interesting to see how much action he actually receives after he has been limited in practice this week. Brady and rookie Jimmy Garoppolo took all of the reps on Sunday and Monday as Mallett was absent, and then got the majority of work Tuesday, Wednesday and Thursday as well.

Garoppolo and Butler building on success. The two most impressive rookies for the Patriots in the preseason opener were quarterback Jimmy Garoppolo and undrafted cornerback Malcolm Butler. Garoppolo said he wants to be consistently good rather than occasionally great, and this is his first chance to string two solid outings together. Ditto for Butler, who is getting a lot of quality reps.

Revis, Browner and defensive penalties. Cornerbacks Darrelle Revis and Brandon Browner were penalized several times over the past three days of practice, and Browner also picked up an illegal contact penalty in the preseason opener. This is part of the NFL's point of emphasis on defensive holding and illegal contact, and referee John Parry said to expect more flags the rest of the preseason. We'll see how Revis and Browner adjust.

Great opportunity for Fleming. With Mayo not participating in practice the past three days, and veteran James Anderson a bit banged up and not expected to play, this is the type of opportunity third-year linebacker Darius Fleming has been waiting for. The former Notre Dame product who missed the first two years of his career with the 49ers because of knee injuries, has been playing both on the line and off the line, and this week was integrated more into the top special-teams mix. He's making a hard push for a roster spot and based on circumstances that have unfolded outside of his control, he should have a nice opportunity to show what he can do Friday night.