Joe Mahoney, AP
Denver Broncos quarterback Trevor Siemian (13) throws against the Carolina Panthers during the second half of an NFL football game, Thursday, Sept. 8, 2016, in Denver. The Broncos won 21-20. (AP Photo/Joe Mahoney)

To football fans and Fantasy Football League players across the globe, the opening Sunday of the National Football League's regular season is like Christmas morning.

And having the NFL's opening weekend fall on the 15th anniversary of the horrifying 9/11 attacks on our country only serves to make today that much more special. After all, those attacks brought about a tremendous, renewed spirit of patriotism in our nation, and what could possibly be more of an American tradition than our own bruising brand of football?

Sure, the 2016 campaign actually opened Thursday night with the defending champion Denver Broncos again turning back the Carolina Panthers in a rematch of last February's Super Bowl.

But that was just one game, sort of a tasty appetizer that helped whet our appetite for what takes place today, when we get the full-meal-deal, a tantalizing smorgasbord of 13 games that will help usher in another edition of our country's most popular sport.

And as the NFL season gets underway, there are some questions that will be answered in the weeks ahead as players and teams try to navigate the always difficult path to the playoffs and, eventually, the Super Bowl.

Questions like:

• Who are all these new starting quarterbacks? And will any of them be able to play up to expectations?

In Denver, Trevor Siemian took over for retired legend Peyton Manning and, with virtually zero previous experience in a regular-season game, all he did in his debut is help lead the Broncos to a come-from-behind victory over the Panthers in Thursday's season-opener.

Rookie QB Dak Prescott takes the reins in Dallas in the wake of veteran Tony Romo's latest injury. Another rookie, Carson Wentz, has been handed the car keys in Philadelphia, which prompted the Eagles to ship veteran Sam Bradford off to Minnesota.

Brock Osweiler, who started several games in Manning's absence last season in Denver, is now the new QB in Houston. And another highly touted rookie, Jared Goff, could wind up being the first-stringer for the Rams, who have returned to Los Angeles after relocating in St. Louis for the last couple of decades.

• Is this the end of the line for Romo?

The Cowboys' oft-injured, much-maligned quarterback suffered a broken bone in his surgically repaired back during the preseason, sidelining him for the first six to 10 weeks of the regular season.

At age 36, and with his lengthy injury history, it may be time for Tony to hang ’em up — especially if Prescott performs the way he did during the preseason.

• Can RG3 resurrect his career in Cleveland?

Robert Griffin III, who not that long ago (2012) was the NFL's Offensive Rookie of the Year in Washington, will try to regain his long-lost magic after enduring a steady downward career spiral with the Redskins.

Unfortunately, he's trying to do it with the Browns, whose list of offensive weapons isn't going to cause much concern for many NFL defensive units.

• Can a large group of high-profile players return to prominence after suffering devastating injuries last year?

Chiefs running back Jamaal Charles and Steelers counterpart Le'Veon Bell suffered season-ending injuries in 2015. Packers wide receiver Jordy Nelson and Panthers wideout Kelvin Benjamin both missed the entire 2015 campaign after sustaining torn ACLs as well.

They're just four of the game-changing stars whose 2015 seasons were cut short or ruined by injuries.

Colts QB Andrew Luck, one of the league's rising stars, missed much of last season with injuries that stalled his budding stardom. Former University of Utah standout Steve Smith of the Ravens and his quarterback, Joe Flacco, both missed the last several games of last year with injuries as well. And several other proven NFL performers (Terrell Suggs, Victor Cruz, Andy Dalton, Jimmy Graham and Tyrann Mathieu, among others) find themselves in the same boat.

Defensive player of the year J.J. Watt of the Texans underwent back surgery this summer and is working his way back into top shape.

These players' return and subsequent effectiveness will have a huge impact on their teams' success this fall.

• How will Jimmy Garoppolo do in his audition as the Patriots' QB?

With Tom Brady sitting out the first four games over the Deflategate fiasco — finally — Garoppolo steps into the void and has a chance to show people that he's a primetime player.

Brady will certainly get his job back as soon as his suspension ends but, in the meantime, the Patriots' QB job is Jimmy's to sink or swim. Whether he becomes the next Tom Brady — or the next Matt Cassel, who turned in a terrific performance when Brady went down with a season-ending injury in the 2008 opener, but failed to live up to that promise in subsequent seasons — remains to be seen.

• How will the Rams do in their return to L.A.?

First, for those of us who grew up watching Merlin Olsen and the "Fearsome Foursome" back in the day, it's nice to see the Rams back in SoCal where they belong. It was tough getting used to calling them the "St. Louis Rams," even though they've been gone from the City of Angels since 1994.

Professional football needs a franchise in Los Angeles, and Los Angeles needs to have a pro football team it can call its own. Hopefully, this time it'll work.

• Who will win the Super Bowl?

It's doubtful that Denver can repeat, regardless of how good the Broncos and their terrific defense looked on Thursday night. And if the Panthers can get back there again, they'd be the favorite to take home the title.

The Patriots, as always, will be in the mix again in the AFC along with the Steelers, and the Bengals, Colts and Chiefs will also be in the hunt. In the NFC, the Seahawks, Packers and Cardinals look like solid contenders this year and could reach the title game if the Panthers falter.

So, as they say in the Olympics (and in speed dating), let the games begin.