The NFL Players Association made a proposal to the league Thursday regarding the terms of the sport’s planned blood-testing program for human growth hormone.

Under the union’s proposal, a population study of NFL players would be conducted before testing would begin. The study would be used to establish a standard for what would constitute a positive test for HGH. Union representatives have maintained that such a study is necessary because established standards for testing might not apply to NFL players, they have said.

The union’s proposal also contains a series of provisions designed to protect players’ rights during the testing and appeal process. A union spokesman confirmed the proposal was made Thursday to the league but declined further comment.

A league spokesman told the Associated Press of the union’s plan, “The proposal is deficient in numerous respects and consistent with the NFLPA’s ongoing strategy to delay testing as long as possible.”

The league and union agreed in their labor deal completed in August that players would be blood-tested for HGH, and targeted the opening of the regular season in September to begin the testing. But the two sides first had to agree to testing procedures. Those deliberations have been stalled and the testing has remained on hold.

Representatives of the league and union met last month on Capitol Hill with leaders of the House Committee on Oversight and Government Reform. Rep. Darrell Issa (R-Calif.), the committee’s chairman, and Rep. Elijah Cummings (D-Md.), the committee’s ranking Democrat, announced after the meeting that blood would be drawn from players soon while the NFL and the union would continue to work out the details of the program.

The league informed the union soon after that it was prepared to begin drawing blood from players. Under the league’s plan, the blood would have been stored without being immediately tested for HGH, pending an agreement on the details of the program. But the union responded that details of the program had to be resolved before blood could be drawn from players.

Details of Thursday’s proposal by the union were posted on a Web site, ProPlayerInsiders, associated with the union. According to the announcement on the Web site, the proposal calls for any player who tests positive to be given access to all testing information. The burden of proof to punish a player would rest with the league and the process would be overseen by a neutral arbitrator, under the union’s proposal. Testing and appeals results would be confidential. No player would be punished until all appeals were resolved and a player would remain eligible to play during the appeal process.

“We agreed to an HGH testing protocol that was safe, one that would be reliable and one that would be that would protect the due process rights of the players,” DeMaurice Smith, the union’s executive director, said in a written statement posted on the Web site. “No one is going to force us into a situation where we don’t accomplish those three things.”