The Rugby Players association says innocent players being labelled drug cheats is a price that must be paid in the fight against performance enhancing drugs.
All Black lock Patrick Tuipulotu has been cleared of any wrongdoing after his B sample showed no presence of banned substances.
He had provisionally suspended after returning a positive drugs test last year.
The chief executive of the New Zealand rugby players association Rob Nichol says they want to know why there was a discrepancy between the two samples but accepts from time to time there will be collateral damage.
"We do accept that if you're going to join this fight against doping, then now and a gain an innocent athlete is going to cop it a little bit."
"You hate to say it but in a way that's part of the cost for fighting such a thing."
New Zealand Rugby says it still has faith in the drug testing process despite the discrepancies shown in the Tuipulotu case.
Chief executive Steve Tew says they now want an explanation from the testing laboratory in Salt Lake City on what happened.
"The beauty of the B sample is clear, obviously something irregular happened in the A sample, but the disappointing thing is that it became public, we tried very hard to honour our confidentiality obligations here so that the player was protected, so that is frustrating but now patrick can now move on with it."
"Clearly the agency involved will now have a look at why the A sample came back the way it did and we look forward to hearing from them in due course."
"If there is something else to come out this it shows how important our drug education policy is," said Tew.
Tuipulotu, who has been training on his own while provisionally suspended, is now free to rejoin the Blues.