It’s long been something of a mantra when it comes to football: Injuries are part of the game.

But at a time in which concerns about player safety have received increased attention in the NFL, a new study by the players’ union casts the medical care offered to players when they do get hurt in a questionable light. Nine in 10 players say they do not trust their team’s medical staff, according to the survey by the NFL Players Association.

“For the last few seasons, there’s obviously been an increased effort on behalf of the league to frame safety issues in the context of who we can punish for on-field contact,” said DeMaurice Smith, the union’s executive director. “The results of the survey show that our focus should be on a much broader field that includes the physicians’ ethical obligation and the duties that doctors have to treat their individuals as patients first.”

It was hardly the type of news the NFL wanted in the days leading up to its annual showcase event, Sunday’s Super Bowl XLVII between the Baltimore Ravens and San Francisco 49ers. But as fans of the Washington Redskins and their star quarterback Robert Griffin III learned four weeks ago, the role of team doctors — who are employed not only to keep players healthy but also to keep them on the field — can be called into question.

Griffin played against the Seattle Seahawks in a playoff game on Jan. 6 with a strained ligament in his right knee. After aggravating the injury early in the game, he was allowed to stay on the field until he suffered a much more severe injury later that required extensive reconstruction surgery.

The passionate back and forth in the days leading up to Super Bowl highlights both the growing concern about the health and safety of football players and the obstacles that lie in the way. “How can you fix it?” said Herman Edwards, a former NFL coach and current ESPN analyst. “You can’t. . . . That’s been going on since mankind, and it’ll always be that way.”

The players’ union study spanned all 32 NFL teams and was conducted late in the season. The NFLPA declined to say how many players responded.

The union asked its members to gauge on a one to five scale how little they trust their team’s medical staff. Seventy-eight percent of respondents said five, meaning they’re not satisfied at all. An additional 15 percent said four, and just 3 percent responded to the question with a one or a two.

“It’s a tricky situation,” said Ravens center Matt Birk, who said he is content with the level of care he receives. “As players, we expect to be safe and we want to be safe. At the same time, we play a very physical game. While I think we can always make strides and always continue to improve the type of care we give our players while they’re playing and after they’re playing, we can’t expect them to take care of everything. Unfortunately, it’s part of the game: Guys suffer.”

League officials defended their practices and their physicians, noting that the collective bargaining agreement between the NFL and the union allows players to seek second opinions at the team’s expense.

“I can tell you that not once during [my] entire time have I ever seen a coach or a general manager ask a physician to do something that was not in the best interest of the player,” said John York, owner of the 49ers. “There’s competition on the field, and there’s player health and safety. Player health and safety comes first.”

The league has ramped up its efforts to identify and treat head injuries and announced Thursday it intends to add an independent specialist on every sideline to help monitor and manage concussions. This doctor would not be on the team payroll. Other injuries would still be treated by doctors employed by the team.

“Make no mistake about it: There’s no game in the world that will have this level of expertise on the field. It looks like a hospital out there,” said Richard Ellenbogen, co-chairman of the NFL’s head, neck and spine committee.

The NFLPA survey speaks to underlying trust issues within the sport, “the pink elephant in the room at every level,” according to Troy Vincent, the NFL’s vice president of player engagement.

“There’s distrust with the league office, a player has distrust with the players’ association, he has distrust with his coach, he has distrust with the medical professionals,” said Vincent, who played 15 years in the league. “But we all have a shared responsibility. . . . That’s a barrier — trust is a barrier.”

While team doctors handle the big injuries and game-day medical care, the team trainers typically handle the day-to-day aches and pains. According to the survey, players were much more pleased with their training staffs. Fifty percent, in fact, said they were satisfied.

Redskins running back Alfred Morris said while he likes the Washington training staff, players entering the league hear stories about the varying quality of medical care offered from team to team.

“[Doctors] are going to do what they’re going to do, even though they work for the team,” Morris said. “There probably are some sketchy ones out there who are going to do, they’re going to lean more toward the owners and stuff. But there are some training staffs that are more concerned about the players or what the team needs and that type of stuff.”

Kent Babb contributed to this report.