Knowles issued a compromise order in which only the court, and not Vilma, may see the documents - including reports of interviews with witnesses - before a subsequent order is made on whether to allow discovery to proceed.
NFL spokesman Greg Aiello said league officials have already discussed the order with Knowles and have agreed to comply.
The order comes a day after Vilma refiled a related lawsuit in the same New Orleans federal court asking for his seasonlong suspension to be overturned. That lawsuit also has argued that the NFL has failed to fully disclose its evidence in the bounty investigation.
The NFLPA filed a similar request on behalf of three other current or former Saints players suspended in the probe: Saints defensive end Will Smith (four games), free agent defensive lineman Anthony Hargrove (seven games) and Cleveland linebacker Scott Fujita (one game).
The players' lawsuits contend that Goodell is incapable of acting as a neutral arbitrator in the bounty matter, in large part because his public statements soon after the NFL's investigation was made public last March indicated that he already had determined the guilt of the players before the disciplinary process began.
Pittsburgh linebacker James Harrison said he has endured "double digit" concussions during his career and is turning to a special sort of padding to help combat the issue.
The four-time Pro Bowler said he has never missed a game due to concussions but began using advanced padding to help deal with future head collisions. Harrison said he began wearing equipment inside his helmet initially developed as body armor for U.S. armed forces about a year ago.
In other news, coach Mike Tomlin said star safety Troy Polamalu (calf) and starting right tackle Marcus Gilbert (ankle) will miss Sunday's against Cincinnati.
Also, Tomlin said he has suspended rookie Alameda Ta'amu two games without pay following the rookie's arrest over the weekend. The 22-year-old fourth-round draft pick was arrested early Sunday morning by police after an incident on the city's South Side. Charges include felony fleeing police, aggravated assault and aggravated assault by vehicle, as well as misdemeanor accident causing damage, resisting arrest, escape and DUI.
* The NFL announced at its meetings in Chicago two games will be played in London next season. The Minnesota Vikings will host the Pittsburgh Steelers at Wembley Stadium on Sept. 29, 2013. The Jacksonville Jaguars will host the San Francisco 49ers at Wembley on Oct. 27, 2013. This is the first time the NFL will play two regular-season games in London in the same season.
St. Louis hosts New England on Oct. 28 in this year's game at Wembley.
In other news from the meetings, Houston, San Francisco and South Florida are bidding for the 2016 and 2017 Super Bowls.
NFL owners will vote next May between San Francisco - the 49ers are building a new stadium in Santa Clara, Calif. - and South Florida for the 50th Super Bowl in 2016. The loser of that race will then compete with Houston for hosting the 2017 game.
* Dallas owner Jerry Jones says it "looks obvious" that running back DeMarco Murray, hurt in Sunday's loss at Baltimore, won't play at Carolina because of his sprained left foot.