Representatives of the NFL, the players’ union and the World Anti-Doping Agency are scheduled to meet Wednesday in Montreal as the league and union continue to negotiate the details of a program to blood-test players for use of human growth hormone.

Several people in the sport said it remains likely that the two sides will complete arrangements in time for players to be tested for HGH beginning with the opening week of the regular season, as they had hoped.

But time is running short for those deliberations to reach a conclusion. There might have to be compromises on some issues for testing to begin on time, said people familiar with the negotiations, who spoke on the condition of anonymity because the talks are at a sensitive stage.

One possibility is delaying the start of game-day blood-testing for HGH. Under that proposal, the other elements of the HGH blood-testing program that wouldn’t take place on game days would be put into effect as scheduled.

NFL Commissioner Roger Goodell apparently is scheduled to participate in Wednesday’s meeting. NFL officials previously have consulted with representatives of WADA, which is based in Montreal, on drug-testing issues. Union officials have sought information from WADA about HGH blood-testing during this set of deliberations.

The new 10-year collective bargaining between the league and the union, which players approved earlier this month, contains provisions authorizing blood-testing of players for HGH. The NFL would be the first U.S. professional sports league to do so with the approval of their union. Currently, HGH is on the NFL’s list of banned performance-enhancing substances, but players are not tested for it.

The labor agreement says “the parties confirm that the [steroids-testing program] will include both annual blood testing and random blood testing for human growth hormone, with discipline for positive tests at the same level as for steroids.”

People on the players’ side have stressed that the players have not approved the details of the testing. If the arrangements are not completed by the league and union, the drug-testing program would be conducted under last season’s rules, without testing for HGH. But under those circumstances, the players also would lose the ability to appeal discipline imposed by the league under the drug program to an independent arbitrator, a provision it gained during the labor negotiations.

Under the program, each player would be blood-tested for HGH once during the preseason. Each player also would be subject to an unlimited number of random tests during the season and as many as six random tests during the offseason.

Goodell said soon after the labor deal was ratified that he expected the details to be worked out in time for the testing to begin when the regular season begins Sept. 8.