On Thursday, the Green Bay Packers faithful received a late Christmas gift: Aaron Rodgers will start Week 17 just under two months after suffering a broken collarbone. Tom Silverstein of the Milwaukee Journal Sentinel broke the news Thursday morning via a report from head coach Mike McCarthy:

Rodgers might show some signs of rust. He may even take a series or two to regain his live-game speed and reaction time.

Barring a disaster, his collarbone shouldn't factor into much else on Sunday, though nothing is certain. It all depends on the answer to one question: Will history repeat itself?

Back in November, Chicago Bears lineman Shea McClellin planted the Packers signal-caller onto his left shoulder—hard.

The hit resulted in the most famous collarbone fracture in sports, and despite him being scheduled to start Week 17, Rodgers' break will continue to heal for the foreseeable future.

In fact, the body solidifies and remodels broken bones over the course of months, not weeks. During that time, a bone remains weaker and less able to absorb impacts while the healing process completes the finishing touches.

On the other hand, the initial, acute phase of Rodgers' collarbone healing is likely approaching its final stages, if it hasn't been there already. The swelling around the bone likely resolved some time ago, and he could work on regaining his function and arm strength immediately thereafter.

Additionally, the fracture site almost certainly sports a strong, solid callus—or healing cartilage transforming into new bone—and, therefore, is able to absorb relatively strong blows.

As for pancake-style hits by 250-plus-pound linemen?

That's another story.

Should Rodgers become the victim of a hit similar to McClellin's from Week 9, the scene could get very ugly, very fast. A second fracture is more likely to displace, almost certainly necessitating its surgical realignment and fixation.

Such is the risk the Packers are willing to take.

Green Bay's coaching and medical personnel surely did not make the decision lightly, either, and make no mistake: Dr. Pat McKenzie and his staff are the best of the world's best when it comes to objectively weighing the medical risks against the football rewards.

Nevertheless, a doomsday scenario wherein Rodgers suffers a repeat fracture that requires surgery could lead to a few to several months of missed time. While almost certainly not a career-threatening situation—and possibly not even one endangering the start of his 2014 season—the decision to place a young franchise quarterback at risk of further serious injury does not come easily.

Why do it at all then?

It's Aaron Rodgers.

The Packers looked anemic after losing their superstar, and it took two consecutive, dramatic one-point victories—as well as a 61-yard field goal from Baltimore Ravens place-kicker Justin Tucker versus the Lions—for Green Bay to even stay in the playoff hunt.

Furthermore, unless Rodgers suffers an aforementioned disastrous hit—and assuming no significant associated ligament or soft tissue damage existed or exists—his collarbone should produce only minimal pain and soreness as the game goes on, if any.

In other words, it's safe to assume he is clear from rehab, strength, flexibility and range-of-motion standpoints, and his left arm and shoulder should serve as more than an adequate counterbalance to his throwing arm.

Said another way?

Unlike a running back returning from a hamstring strain or a wide receiver taking the field after an ankle injury, except a quick bounce-back to form for the 2011 MVP. That is if his offensive line holds up.

If it doesn't, well, hindsight is always 20/20.

Dr. Dave Siebert is a resident physician at the University of Washington. He plans to pursue fellowship training in Primary Care (non-operative) Sports Medicine.