Pulu is in a three-way battle for game time at the Chiefs with fellow All Blacks Tawera Kerr-Barlow and Brad Weber.
That situation has developed quickly, with Pulu emerging strongly last year to put pressure on Kerr-Barlow. When the latter was ruled out for this year's campaign due to injury, Weber was given his chance and took it well, impressing enough to win a test cap against Samoa.
Pulu, who is a Counties Manukau stalwart, is close to Umaga. Conscious of the log-jam at the Chiefs and the lack of genuine halfback options at the Blues, Pulu inquired about making the shift to Auckland.
But he's still under contract with the Chiefs who were not willing to let him go.
Had he been allowed to shift, Pulu would have been a significant, high-impact addition. His abrasive qualities and powerful running would have sat well behind a Blues pack which has potential to grow into one of the better units.
Halfback has been a perennial area of weakness for the Blues. They have the promising Bryn Hall - he missed the 2015 campaign due to injury - but desperately need another high quality option. A combination of Pulu and Hall would have been ideal but isn't going to happen in 2016.
Umaga won't be concerned about the overall contracting situation as he came into the job with a realistic handle on who would be available for next season. Umaga has good knowledge of the junior athletes in the system, having worked with the New Zealand under-20s this year and through his coaching role with Counties.
More than one-third of the title-winning under-20 team play their provincial rugby in the greater Auckland region. Having knowledge of the players is only part of the battle, though. The mistake previous Blues coaches have made is to lack patience in youth.
In John Kirwan's first year in charge, he found himself in a similar position - having to fill the remainder of the squad he inherited with young players.
He picked up Marty McKenzie, Malakai Fekitoa and Waisake Naholo but offloaded them all a year later after barely giving them an opportunity to play in 2013. All of them went on to excel elsewhere and heap the pressure on Kirwan whose lack of patience and willingness to persevere with young players was a major factor in his demise. Umaga is not likely to make the same mistake.
What he understands well is that the transition from ITM Cup to Super Rugby is significant. It's not an easy transition to make and few do it quickly. There's plenty of evidence of that - new All Black James Broadhurst being a good example. The giant lock who made his debut against South Africa overnight has taken more than five years to convert his promise.
It's understood the Blues board have given their unanimous support to Umaga's plan and are comfortable with the likely length of time it will take before the team mature.
