Peyton Manning's passing ability still up in the air

When Peyton Manning returns next season, will he be the same dominant, tempo-controlling quarterback he was before his neck surgery?

According to a leading neurosurgeon on Long Island, the answer to the most important free-agent question this offseason likely won't be clear to everyone -- perhaps even Manning himself -- until he has to make a hard pass at a receiver with a linebacker charging toward him.

Raphael Davis, chair of the department of neurological surgery at Stony Brook School of Medicine, said the bone-fusion surgery Manning had last September is a common one that typically alleviates the discomfort and allows the patient to return to everyday life symptom-free.

But in order to make split-second passes on the fly, a quarterback needs his muscles and nerves to be working in pinpoint and precise cooperation, and Davis said it's impossible to predict whether a person's damaged nerves will recover to that level after surgery.

"You can't assess nerves at time of surgery," Davis said in a telephone interview Friday. "You can't look at nerves and say, 'Gee, it's going to work' or 'It's not going to work.' All you can do is say, 'I did the surgery, I took all the pressure off the nerve and I'm giving the nerve the best chance to recover.'

"And then it's just a question of time and maybe a little bit of luck and see how well the recovery progresses. Most people will progress back to a normal state."

But there's a difference between what qualifies as a normal state for Manning as opposed to the rest of us, which is what makes his free agency all the more captivating.

SEE PHOTOSNFL draft: How these 52 QBs have done

Many teams, including the Jets, lined up for Manning's services the minute the Indianapolis Colts set him free. Though these teams could be acquiring a Hall of Fame-caliber quarterback, they also had to face the reality that it's no sure thing.

At the Colts' news conference Wednesday announcing his release, Manning said he's feeling "closer and closer" to full strength. "I have to remind myself that it is March, and I have a hard time doing it at times," Manning told reporters. "It sure feels comfortable."

When the NFL season opens, it will be nearly a year since Manning had the bone-fusion surgery, the most invasive of the four neck operations he endured.

Davis said it usually takes two to three months to recover from the surgery, adding that there are instances in which patients continue to improve for up to 18 months after the operation. Manning also should be at no greater risk of a significant neck injury, Davis said, because bone fusion surgery "definitively takes care of the problem."

SEE PHOTOSHits & misses: No. 1 NFL draft picks

But significant challenges remain for Manning.

Artem Vaynman, a neurosurgeon with the Long Island-based Neurological Surgery, P.C., said bone-fusion surgeries typically leave patients with up to a 10-percent loss in range of motion in the neck, which could be troublesome for a quarterback trying to avoid sacks.

"Most of the time, it's not noticeable," Vaynman said. "But if you're a professional athlete, that can affect you."

Manning's arm strength also will be closely watched. Both neurosurgeons said the recovery of the nerves will determine whether Manning throws the way he used to.

On that note, Manning said he's still improving with his throwing.

"I still have some progress to make," he said, "but I've come a long way."