Why would Mac Jones get a second opinion on his injury, and how common is that?

Something was clearly wrong with Mac Jones as he was assisted off the field Sunday in Foxborough.Jim Davis/Globe Staff

What does it mean that Patriots quarterback Mac Jones reportedly went to New York this week to meet with a specialist and get a second opinion on his injured ankle?

It could be that Jones and the Patriots are butting heads over how to proceed with his high ankle sprain. Or it could just be a fact-finding mission for Jones, who has never suffered a severe ankle sprain before.

“There are a lot of reasons to get second opinions,” said Dr. David Chao, who was the Chargers’ head physician for 17 years and is now at Sports Injury Central, a website that follows and analyzes sports injuries. “Sometimes players get them routinely for every injury. Sometimes players want to see a specialist. Sometimes there is some controversy over what to do best. And sometimes players do it because they don’t like the answer they got.”

Jones suffered a high ankle sprain Sunday against the Ravens, and he and the Patriots are giving little insight into the injury. Jones missed Wednesday’s practice, and Bill Belichick repeatedly said “day by day” when asked about his availability.

Chao, who has not examined or treated Jones but was simply offering an expert opinion, believes Jones suffered a significant high sprain — at least Grade 2 and possibly Grade 3 — and will be out at least four weeks. It’s even possible that Jones may not return until after the Patriots’ Week 10 bye. The fact that running and scrambling aren’t big parts of Jones’s game could help him return a little earlier, but not by much.

“If this were a running back or a wide receiver, if this were Lamar Jackson, I’d say 6-8 weeks,” Chao said. “But this is Mac Jones. Can he play in the pocket after four weeks? Maybe. But I believe this was a significant sprain.”

Jones hopped off the field late in the fourth quarter after Sunday's injury.Jim Davis/Globe Staff

Getting a second medical opinion is a right afforded to every NFL player per Article 39, Section 6 of the NFL’s collective bargaining agreement. The team is responsible for the costs, as long as the physician is board-certified in his field of expertise, and the player has the right to follow the medical advice of the second doctor. But the player must first consult with the team’s head physician before getting a second opinion, and the team physician must promptly receive a report from the visit.

Article 39, Section 7 also grants a player’s right to choose his surgeon. The team is responsible for the costs but is not liable for any mishaps with the surgery.

Per NFL Media, Jones is getting a second opinion from Martin O’Malley, a foot and ankle specialist at the Hospital for Special Surgery in New York. He also is the Brooklyn Nets’ team doctor.

Jones’s visit to O’Malley could just be a case of him wanting to visit with a foot/ankle specialist to discuss his rehab timeline and whether he needs surgery. A head team physician in the NFL can perform foot and ankle surgeries, but that isn’t necessarily his area of expertise.

“For regular patients or NFL athletes, if a doctor says you shouldn’t get a second opinion, then you should run to get one. It’s your right to do so,” Chao said. “As head team physician, I used to tell players all the time to get a second opinion if you want one. Just make sure it’s with a quality doctor.”

One issue could be whether Jones needs a procedure called “tightrope surgery,” which has been popularized by Alabama football players in the last few years, most notably Tua Tagovailoa.

At the end of the 2018 season, Tagovailoa’s return from tightrope surgery after just four weeks created the impression that the procedure can speed up the recovery from a high ankle sprain, but Chao said that isn’t the case.

Tagovailoa was able to play on his high ankle sprain for three quarters before a different injury knocked him out of the game. His sprain wasn’t nearly as significant as the one believed to have been suffered by Jones. Tightrope surgery, which Chao said isn’t common in the NFL, isn’t likely to get Jones on the field sooner.

What does the rest of the season hold for Jones?Jim Davis/Globe Staff

“Tightrope surgery does not help you heal any faster,” Chao said. “The tightrope is to hold the two bones in the correct place. It does nothing to directly heal the ligament. It does stabilize the ankle, and it has some effect on being able to rehab earlier, but it doesn’t speed up the timeline.

“It’s standard in the NFL you don’t do surgery on a high ankle sprain unless it’s unstable or displaced, and then of course you do the tightrope procedure, or a dynamic suture wire fixation. But traditionally, it’s not done often in the NFL.”