The NFL will not begin blood-testing its players for human growth hormone at the start of the season as targeted, the league informed team owners Friday.

As part of their 10-year labor deal completed last month, the league and the NFL Players Association agreed that players would be blood-tested for HGH annually and also would be subject to additional random testing.

But the two sides first had to agree to testing procedures, and their negotiations on that subject have been at a standstill. The union has expressed reservations about the reliability and safety of the test. The NFL has maintained that the test is both reliable and safe.

“Although the CBA [collective bargaining agreement] reflects a commitment to implement such testing by the start of the 2011 regular season, it is apparent that we will be unable to do so because of the union’s continued refusal to accept the validity of the tests developed by the World Anti-Doping Agency that are used in Olympic sports and minor league baseball,” Jeff Pash, the NFL’s executive vice president of labor, wrote in a memo to owners. A copy of the memo was obtained by The Washington Post.

It is not clear when the impasse between the league and union might be broken for testing to go into effect. People familiar with the deliberations previously left open the possibility of the testing being implemented at some point during the season, and Pash wrote in his memo that the league “will continue our efforts to address the union’s questions.”

George Atallah, the union’s assistant executive director of external affairs, said in a telephone interview: “We will continue to work with the league to implement a fair and safe test. We continue to believe the integrity of the game is critically important, but so is the health and safety of our players.”

Representatives of the league and union met last week in Montreal with WADA officials. But union officials emerged from the meeting saying their questions about the HGH blood-testing had not been answered adequately.

HGH is on the NFL’s list of banned performance-enhancing substances but players are not tested for it. The NFL would become the first U.S. professional sports league to blood-test players for HGH with their union’s approval. Minor league baseball players, who are tested, are not represented by a union.

SUSPENSIONS: Defensive tackle Kevin Williams and three others have been suspended for the first two games of the regular season and fined an addtional two paychecks for violating the league’s policy on performance-enhancing substances, ending a three-year court fight.

Also suspended were New Orleans defensive end Will Smith and two players currently without teams: defensive tackle Pat Williams and defensive end Charles Grant.

In a separate judgment, Ravens wide receiver David Reed was without pay for the season opener against the Pittsburgh Steelers and fined an additional game check stemming from an incident last year in which police discovered marijuana at his residence.

B EARS: Unhappy with his contract, six-time Pro Bowl linebacker Lance Briggs told the Chicago Tribune he is seeking permission to look for a trade. He said agent Drew Rosenhaus has filed a formal request to seek a trade.

COLTS: Former Ohio State coach Jim Tressel was hired by Indianapolis as a game-day consultant to help determine when the team should challenge plays.

EAGLES: Backup quarterback Vince Young is considered day-to-day after he strained his hamstring in Thursday’s preseason game vs. the New York Jets.

— Associated Press