The NBA and National Basketball Players Association are close to an agreement to test players' blood for human growth hormone (HGH), according to sources directly involved in the talks who spoke to ESPN. Testing could begin as early as next season.

HGH has been included on the NBA's list of banned substances for quite some time, however, has never been tested for. To test for this substance, the NBA would have to collect player's blood, which the union has never allowed, and there was little agreement about the test's reliability.

However, a talks between the league and union have become increasingly serious as of late and concerns have reduced. A decisive factor is the success of Major League Baseball's HGH blood tests, strengthening the NBA's claim for the test being more reliable.

Terms of the 2011 NBA collective bargaining agreement created a committee to hash out the particulars of HGH testing. Progress had been slow until recently.