However happy and relieved Patrick Tuipulotu may have been to be exonerated of a doping charge today, Blues coach Tana Umaga was probably celebrating harder.

As much as it put Tuipulotu's season back on track, so too did it lift the potential fortunes of the Blues who were beginning to feel a level of angst about what they would be able to do to bolster their resources at lock

But they have no need to worry about that now as Tuipulotu has been cleared to resume training and playing with immediate affect after his B-sample tested negative. That result ended two months of frustration and difficulty for Tuipulotu who has been struggling to understand why he failed a drugs test in November last year.

The big lock was provisionally suspended by World Rugby following the positive result after playing for the All Blacks against Ireland in Chicago. He was genuinely shocked and perplexed that he had failed. He was adamant that he had not deliberately or knowingly taken a banned substance and nor was he aware of any product that he could have inadvertently consumed that would result in him testing positive.


Still, having failed a test, he was left in limbo until he either had a negative B-sample or completed a hearing where he would have the chance to plead his case and try to persuade the relevant agency that he was innocent of any deliberate wrong doing.

He had been advised that a negative B-sample would be a rarity in the extreme and yet he returned one - heightening the probability that a mistake was made by the WADA-accredited laboratory Sports Medicine Research and Testing Laboratory (SMRTL) in Salt Lake City where his original sample was tested.

New Zealand Rugby Players' Association boss Rob Nichol said inquiries will continue to determine why the A-sample did fail.

"This is a matter that SMRTL is investigating and we look forward to their feedback," said Nichol. "Working with Patrick through the process, we always felt confident that he would be cleared," said Nichol.

"To be honest, there is an element of frustration, given the initial result and publicity, but at least people now know Patrick did nothing wrong. This result also reinforces the importance of the regulations and strict confidentiality obligations regarding players and their rights. Patrick was unfairly labelled as a result of the premature publicity of this matter. We trust that everyone now has a greater level of understanding in this regard."

Tuipulotu hasn't been able to train with the Blues squad since his suspension but is understood to have trained on his own and is in good physical shape. He'll work through with Blues and All Blacks conditioning staff when he should return to play but, despite the uncertainty over the summer, it's probable he'll be available from the beginning of March if not sooner.

And for the Blues, the relief will be considerable. They have a backline that has incredible potential but without Tuipulotu, they may have struggled to win the ball, or deliver the sort of grunt and graft required to compete with the best teams.

His return to the boiler room will give the Blues presence in the collisions and also a dynamic ball-carrying force.