The clock begins ticking once again for Tom Brady and the New England Patriots on Thursday, when the team opens training camp at Gillette Stadium in Foxborough, Massachusetts.

Brady turns 37 on Aug. 3. His window – and New England’s – for another Super Bowl championship is closing.

As the Patriots begin preparation for their opener at Miami on Sept. 7, Brady and Coach Bill Belichick are facing many questions. Here are five to consider:

1. Who will step up at wide receiver?

Julian Edelman, nicknamed MiniTron by Brady last year (a reference to Detroit’s Calvin Johnson, otherwise known as MegaTron), is the closest thing the Patriots have to a No. 1 receiver. A former college quarterback, the 5-foot-10 Edelman caught 105 passes for 1,056 yards and six touchdowns last year in a breakout season. But Brady needs more help, especially if tight end Rob Gronkowski isn’t healthy. Gronkowski is one of the NFL’s most potent weapons, but he has missed 14 games the last two seasons because of injuries. Gronkowski told reporters last week that he plans on playing the entire season, which means he feels he’ll be ready for the opener at Miami on Sept. 7. That doesn’t mean he’ll be ready for the start of training camp, but the Patriots hadn’t placed him on the PUP (Physically Unable to Perform) as of Tuesday.

The Patriots signed Brandon LaFell as a free agent from Carolina to take some of the burden off Edelman. But LaFell has never caught 50 passes in a season. Danny Amendola returns for a second season and gives the Patriots a nice threat in the slot – if he can stay healthy. He missed four games last year.

That leaves the trio of second-year receivers returning that Brady relied on so heavily last year. Aaron Dobson has the most potential, but is recovering from offseason foot surgery. Kenbrell Thompkins and Josh Boyce have shown flashes of talent, but need to become consistent. One of those three has to step up to give Brady downfield threat.

2. Will the young guys step into starting roles on the offensive line?

The offensive line was one of the biggest disappointments last season. A veteran, talented group got pushed around nearly every week, which is probably why the Patriots invested so heavily in offensive linemen during the NFL draft.

They took three: center Bryan Stork (Florida State), guard Jon Halapio (Florida) and tackle Cameron Fleming (Stanford). Stork and Halapio are expected to push for starting jobs against center Ryan Wendell and left guard Dan Connolly. Connolly has a big contract ($4 million) and if the competition is close, don’t be surprised if the Patriots go with the younger (cheaper) talent. Marcus Cannon, who has filled in at guard and tackle the last two years, could also win that spot. Guard Logan Mankins and tackle Nate Solder are very good on the left side of the line, but both need to play better than they did last year.

3. How do cornerbacks Darrelle Revis and Brandon Browner change the Patriots’ defense?

The Patriots suddenly have a secondary that can shut down a passing game. Revis is considered one of the best, if not the best, cornerback in the game. Browner, at 6-4, 221 pounds, has the speed and strength to shut down anyone. He will miss the first four games because of a suspension for violating the NFL’s substance abuse policy. Combine them with Devin McCourty at safety and you have three extremely talented pieces. The only secondary position that is uncertain is the other safety spot, where second-year pro Duron Harmon has the inside track.

If the secondary can force a quarterback to hold the ball for another second or two, the pass rush will be much more effective. Rob Ninkovich and Chandler Jones provide great pressure from the outside. Vince Wilfork (Achilles surgery) and Tommy Kelly (ACL surgery) provide stout inside play if healthy. First-round draft pick Dominique Easley has the ability to either stuff the run or rush the passer. The linebacking corp is solid, with Jerod Mayo, Dont’a Hightower and second-year pro Jamie Collins, who had several strong games at the end of the season when Mayo was injured.

The Patriots should be strong against the run with that front seven. The revamped secondary should put this defense at another level.

4. Can Stevan Ridley regain Bill Belichick’s trust?

Belichick has always valued ball security more than anything else from his running backs. If the ball is in your hands, don’t lose it.

Ridley has to once again prove he can hold onto the ball. After rushing for 12 touchdowns and more than 1,200 yards in 2012, he couldn’t hold onto the ball – or his starting spot – in 2013. Ridley lost four fumbles last year and found himself benched for one full game and long stretches of others. Ridley gives the Patriots their best chance of establishing a power running game.

Shane Vereen is great as a change-of-pace back and Brandon Bolden gives an occasional burst. And let’s not forget draft pick James White, out of Wisconsin. He’s more of a Vereen-type of back, but fumbled only twice in 754 career touches. He could be a difference maker – if Ridley can’t hold onto the ball.

5. How much does Brady have left?

He’s not getting any younger.

Brady comes into this season with some national writers doubting whether he’s an elite quarterback any more. That’s foolish.

Yes his statistics took a dip last year – his lowest completion rate (60.5) since 2004, fewest passing yards (4,343) since 2006 and fewest TD passes (25) since 2009 – but you have to consider his cast of receivers when looking at those numbers.

Brady has made a lot of marginal NFL receivers look pretty good over the years.

And he did as well as he could, often willing the team to victory. Five times he brought the Patriots back in the fourth quarter and he took them to the AFC championship game for the third consecutive year.

Can he do it again?

Well, all this talk of his decline has probably given Brady another chip on his shoulder. And we know what happens when he plays with a chip like that.