The Patriots have their first off day Monday, so let's take an early stock of what looks good and what hasn't so far after four practices:

Looking good:

  • Tom Brady and the passing offense: They all look in mid-season form. The addition of viable wideouts like Brandon Lloyd, Jabar Gaffney, and Donte' Stallworth already has had an impact. The Patriots have completed more deep passes so far than they did all of last camp.
  • Aaron Hernandez: The third-year tight end has dazzled so far with his ability to get open against a variety of coverages. The thing is, he's probably more dangerous after the catch.
  • Jerod Mayo: The linebacker had a few struggles last season because of injury and instability in the lineup. Back in a play-making role at WLB, Mayo has been all over the field -- rushing, stopping the run and defending the pass. Hopefully the team stays healthy to keep him there.

Some worry:

  • Offensive line: The Patriots have been the model of stability on the line during much of Brady's career. That's over, at least for now. With only one projected starter in the lineup at his rightful spot (LT Nate Solder), the Patriots are a work in progress. The entire unit has struggled even before you get to the reserves.
  • Secondary: Still very shaky. They've been shredded to this point but an outstanding offense. Devin McCourty has not shown much improvement yet, and were waiting to see CB Ras-I Dowling start making some plays. Some questions also about free-agent safety Steve Gregory.
  • Rob Gronkowski's health: You knew it wasn't going to be perfect after offseason ankle surgery, and it hasn't been. Not a ton of worry yet, but if Gronkowski's average play starts to linger, the Patriots might have to think about resting him.

Follow Patriots reporter Greg Bedard on Twitter: @CBSSportsNFLNE.