They are seeking clarification on whether Nelsen's impending shift into management will preclude his involvement in the All Whites' World Cup qualifiers in March. Nelsen is under contract at QPR until the end of the English season and, if he is unsuccessful in seeking an early release, his retirement may be postponed until May.
New Zealand will seal their progression to the inter-continental playoff later this year if they beat New Caledonia at an undetermined venue on March 22. If Nelsen were to continue with QPR, he would surely be selected and the game could double as something of an international swansong, which may also see it played in Nelsen's home town of Christchurch.
Herbert said it was too early to speculate on that possibility, though he remained hopeful Nelsen would be available to help the All Whites advance out of the Oceania region.
"It's not my position to say whether Ryan's retired or not. At this stage, I believe he hasn't," Herbert said. "It's a massive move in his life. [Toronto] is a great step for him, a real challenge again.
"But let's wait and see. I don't know what his commitments to QPR are - is that to the end of the season? If that's to the end of the season, does that give him a shot to play in the March window?"
Another possibility was Nelsen being retained within the national set-up in some form, especially if the All Whites qualify for next year's World Cup in Brazil, but Herbert said there were many variables to consider before such a role could eventuate.
Herbert had tried to reach Nelsen earlier in the week but said he would now wait for him to discuss the matter with QPR manager Harry Redknapp.
"It's not my position to ring and ask him, 'Ryan, the media's asked me if you're retiring, are you retiring?' If he makes that decision then, 100 per cent, we'll talk about that.
"I don't want to be the one who's talking about or pre-empting someone's retirement. Because, when I went through it, it's really personal, you kind of keep it to yourself."
Herbert said Nelsen was facing a tough task in going to a side which finished bottom in the MLS last season, but he was confident his charge would rise to the challenge.
"It's about 20 years I've been in coaching and I think it takes time. The good thing that he's got is he's going into a big club with big resources, probably a bit of money to spend in a huge, exciting league.
"That's the challenge that he faces but he enjoys that. Personally, I think he'd be up for it.''
