I do not know how you would negotiate that quid pro quo.
The CBA sets training camp rules (this was from 2016 but I do not think it has changed for 2017)
Every training camp is governed by the rules of the NFL's collective bargaining agreement. Here are the rules pertaining to training camp practices:
*The first day of training camp is limited to physical exams, meetings and classroom instruction. Running and conditioning are the only on-field activities permitted.
*No contact is allowed and no pads can be worn on the second and third days of training camp.
*After the third day of training camp two-a-days are permitted with the following restrictions:
*Players may be on the field for a total of no more than four hours per day.
*Players may participate in no more than one padded practice per day, which shall be no longer than three hours of on-field activities.
*There must be at least a three-hour break after the first practice.
*The second practice on the same day may only be for a maximum of the remaining available on-field time and has to be limited to only walk-through instruction (no helmets, full-speed pre-snap and walking pace after the snap).
*The three-hour limit on padded practices begins as soon as position coaches start to coach players on the field.
*If a team begins a padded practice but the practice is canceled within 60 minutes of its start due to inclement weather or any other reason beyond the team's control, the practice won't count as a padded practice.
*A padded practice is defined as a practice in which players are required to wear helmets and shoulder pads.
*Teams are required to film all on-field activities during training camp. A copy of the film needs to be maintained until 30 days after the start of the regular season. The NFLPA can view the film if a player files a complaint alleging a violation of the training camp rules.
http://www.nj.com/giants/index.ssf/2...amp_rules.html
The CBA also sets the max number of regular season padded practices (this in an article regarding the Canadian league eliminating all regular season padded practices)
The NFL's current CBA limits teams to 14 padded practices during the regular season, 11 of which must come in the first 11 weeks of the season. Teams are not required to use them all, and some don't.
http://www.espn.com/espn/story/_/id/...ason-practices
You might get the owners to agree to reduce the number of preseason games (probably in return for at least one more regular season game to make up for the two preseason games that are included in season ticket packages) in return for more padded practices but I do not see how you could get coaches to agree as a CBA matter how many reps each player got in preseason games (which any marginal player trying to make the team would not want because it might result in them getting cut)
NFL wants to avoid injuries and blows to the head but that is, for better or worse, how the game has been played