FOXBOROUGH, Mass. -- The Patriots have fallen behind the Arizona Cardinals by a score of 6-3 at the end of the first quarter. The top storyline from the quarter was what looked like a right ankle injury to tight end Aaron Hernandez, who was helped to the locker room by members of the Patriots' medical staff. The team announced his return to the game as questionable.

Passing along other observations from the opening period of play.

1. Welker not in to start game. Patriots wide receiver Julian Edelman was inserted into the starting lineup in place of Welker on Sunday, a situation of note after Welker was limited to 43 snaps in Week 1. Welker entered the game on the team's second drive (the first drive lasted just a single play), and has played a handful of snaps since. Hernandez's injury might be a reason we are seeing more of Welker.

2. Other starting notes. Reserve cornerback Sterling Moore appears to have elevated above Ras-I Dowling in the Patriots' nickel defense. He earned the reps as the team's star corner, with Dowling not logging any defensive snaps. On offense, it was Donald Thomas in at right guard in place of Dan Connolly, who left last week's game with a head injury.

3. Defense bends, doesn't break again. For the second consecutive week, the Patriots allowed an opponent to drive down the field to start the contest, but once again the Patriots tightened up when it mattered most. Like the Titans a week ago, the Cardinals were able to run the ball with relative effectiveness on their opening drive, as well as convert on a pair of third downs.

4. Brady passes Unitas. Patriots' quarterback Tom Brady passed Johnny Unitas for 13th all-time on the NFL's career passing yard list on a 16-yard completion to running back Stevan Ridley.

5. Penalty Box. Nose tackle Vince Wilfork was flagged for an offsides penalty, the lone of the quarter for New England.