NEW ORLEANS – So much for labor peace in the NFL.

Less than 18 months after the league and players ended a lockout by signing a 10-year collective bargaining agreement, NFL Players Association executive director DeMaurice Smith and union president Domonique Foxworth used a Super Bowl news conference to lay out a series of complaints about safety issues Thursday.

Smith began by threatening to file a grievance if the NFL refuses to institute a system to verify the credentials of all medical personnel on the 32 teams. He mentioned three amendments the NFLPA wants to make to the new CBA, including the appointment of “a neutral chief safety officer who can hear appeals about acceptable levels of medical care.”

He called the NFL’s lockout of its officials at the start of this season “one of the most deliberate disregards of player safety that I think has occurred in the National Football League since our inception.”

All in all, it sent a clear message that the union and owners have significant differences about how to improve players’ health and safety.

Even when the sides do agree, they can’t seem to agree.

The union has been pressing the NFL to put independent neurological consultants on sidelines during games to help diagnose and treat concussions, something league general counsel Jeff Pash announced at a news conference earlier Thursday he expects to begin next season.

But Smith would only acknowledge having “heard that they have relented, at least in some respect, to have sideline concussion experts. We have not seen the proposal.”

Pash did say that “details need to be worked through” with the NFLPA.

The NFL is facing concussion-related lawsuits from thousands of former players. In a series of interviews about head injuries with The Associated Press in December 2011, 31 of 44 players said they wanted the league to have independent neurologists at games.

At its media session Thursday, the union presented the results of an internal survey that it said showed a majority of players are not satisfied with the way their team manages injuries and that most do not trust their team’s medical staff. The union would not say how many players participated, however.

“The league, their No. 1 focus — at least they say their No. 1 focus — is health and safety. And we say our No. 1 focus is health and safety,” Foxworth said. “How come we have such a hard time moving the ball on some health and safety issues?”

He mentioned the use of replacement officials, the NFL’s desire for an 18-game season, the increased slate of Thursday night games and the New Orleans Saints bounty investigation as examples of items that have driven a wedge between the players and the league.

“All those things are happening, and our players see it,” Foxworth said, “and they lose trust.”

PRACTICE: San Francisco practiced outside for the first time in New Orleans, and Baltimore was briefly right nearby.

A day after their Super Bowl preparations were moved indoors because of high winds, Coach Jim Harbaugh’s 49ers shared the Saints’ facility with big brother John’s Baltimore team after it moved from Tulane University.

Jim Harbaugh called the 100-minute session a “photo copy” of the outstanding practice Wednesday, which safety Donte Whitner considered the best all year.

San Francisco overlapped for 10 minutes with the Ravens, with drapes from local merchants used to separate the practices and ensure privacy. Jim Harbaugh credited the collaborative effort to “cooperating spirits.”

Linebackers Aldon Smith and Ahmad Brooks were limited in practice for the second day with shoulder injuries.

ALEX SMITH leaving the 49ers after this season is a topic CEO Jed York isn’t ready to address.

York made one thing clear: Smith hasn’t requested his release after losing his starting quarterback job to Colin Kaepernick.

Smith certainly hopes to remain a starter somewhere, and that doesn’t seem likely anymore with San Francisco, his only NFL team.

While the 49ers would love to have two winning QBs, York realizes that might not be a realistic luxury as far as Smith is concerned.

“Alex and I started with the 49ers the same year in 2005 and I’ve known Alex for a long time. And that’s part of the overall analysis you do at the end of the season, not just for one player but for everybody,” York said.

“And you figure out what’s best for guys, what’s best for the team. Is there a spot for him on the team from a cap standpoint? Yeah, absolutely there’s a spot for him on the team. From a need standpoint, it’s pretty nice to have two quarterbacks that you feel that you can win with. Is there going to be a demand for a quarterback who’s played as well as he had the last couple years? Yeah.”

AN ODDITY for this Super Bowl has both teams’ former owners as finalists for the Pro Football Hall of Fame.

The late Art Modell, who owned the Cleveland Browns, then moved them to Baltimore to become the Ravens, and Ed DeBartolo Jr., of the 49ers could enter the hall Saturday. They are among 15 modern-day finalists; as many as five can be elected.

DONALD DRIVER, the career leading receiver for Green Bay, announced his retirement, then helped kids from Junior Achievement sell lemonade at a pop-up stand in the Super Bowl media center.