The leaders of a Congressional committee told the NFL Players Association Monday that they intend to “communicate directly with the players” on the issue of whether the sport should blood-test players for use of human growth hormone.

Rep. Darrell E. Issa (R-Calif.), chairman of the House Committee on Oversight and Government Reform, and Rep. Elijah E. Cummings (D-Md.), the committee’s ranking Democrat, outlined their plan in a letter to DeMaurice Smith, the executive director of the players’ union.

“While NFLPA management may not believe that HGH is a problem in the NFL, the words of your athletes suggest otherwise,” Issa and Cummings wrote in their letter to Smith, dated Monday. “…Although you have requested previously that we communicate directly with the NFLPA on these matters, we now ask that you and your staff not interfere with our efforts to communicate directly with the players or their personal counsel.”

The league and union agreed as part of their 2011 collective bargaining agreement that players should be blood-tested for HGH. But the two sides still have not agreed to the details of the testing program. Two NFL seasons have been played without it.

HGH is on the sport’s list of banned performance-enhancing substances but players are not tested for it.

Most recently, the league and union have been unable to launch a population study that the union has maintained is necessary to determine what should constitute a positive test for athletes the size of NFL players.

Issa and Cummings previously have been unsuccessful in their attempts to push negotiations forward.

“We are disappointed with the NFLPA’s remarkable recalcitrance, which has prevented meaningful progress on this issue,” they wrote in Monday’s letter. “We intend to take a more active role to determine whether the position you have taken—that HGH is not a serious concern and that the test for HGH is unreliable—is consistent with the beliefs of rank and file NFL players.”

In the letter, Issa and Cummings asked the union for documentation about its negotiations with the league regarding the population study and the implementation of the blood-testing program. A news release from the committee warned the union that “players may be called before” the committee.

George Atallah, the union’s assistant executive director of external affairs, said in a written statement: “We will cooperate with the Committee as we have throughout this process. If the Committee is interested in asking us to be a part of a hearing, then we would certainly welcome that.”