GREEN BAY - If Aaron Rodgers had been rolling left when Minnesota Vikings linebacker Anthony Barr drove him into the ground Sunday, the Green Bay Packers' two-time MVP quarterback would have real hope of returning this season.

Rodgers already has overcome a fractured left collarbone in his career. It cost him seven games in 2013 before he returned for the regular-season finale, and then the playoffs. This time, Rodgers broke his collarbone three weeks earlier in the season.

But he wasn’t rolling left.

Rolling right, Rodgers had his throwing shoulder slammed into the field. Barr finished the play falling on top of Rodgers, the force of his weight driving the Packers quarterback’s right shoulder into the turf.

Luga Podesta, a regenerative orthopedic specialist at Bluetail Medical Group in Naples, Fla., watched video of Barr’s hit and Rodgers’ subsequent crash. It’s a play Podesta said he has seen many times.

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Podesta is a former training camp medical consultant with the Dallas Cowboys and New Orleans Saints. He knows what it looks like when a quarterback breaks his collarbone.

This, he said, was a classic example.

“He fell right on the tip of his shoulder,” Podesta said, “which is usually how it breaks. Especially if someone lands on it.”

A fracture to Rodgers’ right collarbone is why the Packers are staring at the likelihood of playing the rest of their season without him.

Coach Mike McCarthy said Monday that Rodgers will undergo surgery in the near future to repair his broken collarbone. No date has been set for surgery, McCarthy said, but “potentially the season could be over” for his quarterback.

This kind of fracture, according to multiple orthopedic specialists, can require a month-longer recovery when it happens in a quarterback’s throwing shoulder. Tim Gibson, an orthopedic surgeon at MemorialCare Orange Coast Medical Center in Fountain Valley, Calif., said Rodgers’ next meaningful pass likely will come in the 2018 season.

“Because it’s his throwing arm,” Gibson said. “That does affect it more than if it was his non-throwing arm. If it’s near the end of the bone or it’s shattered, then I think that would be probably without a question (out for the season). If it’s in the middle and it’s clean, even though it might be healed in eight weeks, his arm strength and accuracy and all those things – he can’t really practice in the meantime. Whereas, when he broke his other one, he could still throw the ball within a short period of time after the injury.

“This one, there’s not going to be any throwing for some time. So it could be that it’s a worse injury, or it just could be that on that arm the return to play is going to be delayed because of other aspects.”

The type of fracture (clean or shattered?), location of fracture (mid-clavicle or near the joint?) and amount of displacement (are the fractured bones touching or not?) all will factor into determining the length of Rodgers’ absence.

In the best-case scenario, Gibson said, Rodgers could return to the field as early as 10 weeks after injury. That would put Rodgers on track to play late in the season. It’s also likely Rodgers will require more time.

Podesta said almost 80 percent of collarbone fractures happen mid-clavicle, between the sternum and AC joint. That would be good news for Rodgers. Fractures near the end of the collarbone, Podesta said, can take longer to heal.

With the injury in his right shoulder, the Packers are at the mercy of how long it takes for Rodgers’ bone to heal. Each week Rodgers’ throwing arm is immobile, it will become weaker. If it’s a clean break, Podesta said, Rodgers’ right arm could be in a sling three to four weeks.

Around six weeks, Podesta said, Rodgers could start strengthening his shoulder. It could take another three to five weeks for Rodgers to begin throwing.

“He doesn’t get back for probably about three months,” Podesta said, “if not more.”

Three months would put Rodgers on course to return in the middle of January. By then, the Packers' season almost certainly would be over.

Gibson said it has become the trend for broken collarbones to be surgically repaired, though it doesn’t always happen. Rodgers did not require surgery in 2013.

Surgery does not require significantly more recovery time, Gibson said. Rather, Gibson suggested the decision for Rodgers to undergo surgery likely depended on the fracture pattern and bone displacement. If the pieces of Rodgers’ fractured collarbone were touching, they would have been more likely to avoid surgery. With a clean break, a surgeon can insert a metal plate with screws to fuse the bones together. Depending on the fracture, a surgeon can also insert a rod into the clavicle.

“If it’s not off by much,” Gibson said, “it can heal without surgery in eight to 12 weeks. So there are fractures that do not have surgeries. Not doing surgery does have potential advantages, being you don’t have a plate in there that has to have a second operation. So some that heal without surgery long term are nice, because there’s no second operation to take the plate out, which can be symptomatic.”

At worst, Podesta said, a fractured collarbone should allow Rodgers to return next season.

He said range of motion in Rodgers’ shoulder won’t be an issue long term. Rodgers likely will undergo an aggressive strength-building program this offseason, Podesta expects.

“The best way to actually strengthen it,” Podesta said, “is by moving it and him actually throwing.”