NEW ORLEANS -- NFL owners are expected to vote Tuesday on potential changes to the kickoff rule designed to increase player safety.

While this could lower the production of kickoff return standouts, such as the Vikings' Percy Harvin, there is a chance Harvin won't be returning kicks as much. He has battled migraines since childhood, and the high-impact of collisions during returns doesn't help. And Lorenzo Booker averaged 23.8 yards on 18 returns after joining the Vikings last December.

"You take a look at what we did at the end of the year with Booker returning even though Percy was ready to go -- you have to consider the things you just mentioned [about Harvin]," Vikings coach Leslie Frazier said at the NFL owners meetings. "Booker did a great job for us.

"That was one of the reasons I told [Harvin], 'Hey, you know what? Don't worry about kickoff returns this game. We're going to let Lorenzo handle it and you're going to make big plays for us as a wide receiver.' ... That's not to say it'll always be that case. But if you have a guy like a Lorenzo who gives you something, you don't always have to put Percy back there."

Some NFL coaches expressed concerns about some of the suggested changes to kickoffs -- moving them from the 30-yard line to the 35, placing the ball at the 25-yard line instead of the 20 after touchbacks and eliminating the two-man wedge.

The NFL's Competition Committee is going to exam exactly how many alterations would be made before representing the proposal to owners for a vote.

Peterson's contract Once the work stoppage ends the Vikings almost certainly will have to address the contract situation of Pro Bowl running back Adrian Peterson.

Peterson, whose contract voids after the coming season, will be looking for an extension and the Vikings certainly would like to reduce the amount ($10.7 million base salary) he is owed in 2011.

"I'm not going to comment on any contract negotiations, but needless to say, as everyone knows, Adrian Peterson is a very important player on our ballclub," owner Zygi Wilf said. "But when it comes to contracts, we'll wait and see."

The latest motion Facing an April 6 hearing in U.S. District Court on the players' motion for a temporary injunction that would stop the NFL lockout, league lawyers asked a federal judge to keep the lockout in place.

The NFL's stance is that the players' association decision to decertify is a sham. The league wants the federal court in St. Paul to wait for the National Labor Relations Board to rule on an unfair labor practice charge against the former union. Meanwhile, NFL owners were briefed by Commissioner Roger Goodell and the league's lawyers on Monday.

Etc. • Asked about the decision by Vikings ownership not to layoff any staff members or cut pay at the outset of the lockout, Wilf said: "It's very important to let everyone know that we felt the hard work that they've been putting in, and continue to put in, was very important to our organization and that as an organization policy we wanted to be consistent and thinking of everyone and the hard work they put in." Wilf has not considered what he will do if the lockout is extended.

• The Vikings hired former Citadel assistant coach Cameron Turner as assistant to the head coach. Turner replaces Dennis Polian, who has decided to pursue other options.

• Vikings cornerback Chris Cook had an advisement hearing Monday on a misdemeanor gun charge in Lynchburg, Va. Cook's attorney Mark Arthur said his client, a second-round pick last year, is scheduled for a May 6 hearing at which he will plead not guilty.