The 23-year-old attacking midfielder is scheduled to arrive in Wellington late on Friday, and Herbert said he's a good chance for a start on Sunday when Phoenix tackles Newcastle Jets at Westpac Stadium.
Rock bottom Phoenix has won just four time from 17 matches as it struggles to adapt to a new, possession-based style of football.
Olyroos midfielder Cernak has made 21 appearances for Melbourne Victory since the start of last season, after previous spells with Brisbane Roar and North Queensland Fury.
Herbert believes he'll offer plenty of zest in the struggling midfield.
"He's technically good, he'll be a good presence in the side and he's a new face around the group.
"We've bought him as an attacking midfield player, so hopefully he gets himself forward and into the box. He's probably that little bit more creative, and creates opportunities for other players as well."
Captain Andrew Durante said Cernak is an exciting player, who should add another dimension to the midfield.
"He's more of an attacking midfielder - he can play wide, but I think he's probably better suited to us playing in the middle.
"I'm not saying he's the answer to turning the season around, but a fresh face around camp is always nice, and hopefully he can play a part in the weekend."
Meanwhile, Herbert blew the whistle on answering questions about club co-owner Gareth Morgan's broadside at fans, while Durante chose his words carefully in appealing for continued support.
In an interview recorded a week ago but only aired on Thursday, Morgan labelled fans of his A-League club unsophisticated, pathetic and unable to absorb short-term pain for long-term gain.
Morgan said Phoenix supporters are in favour of a style change, but aren't willing to accept it will take time.
He accused fans of not keeping the club's interests at heart.
"Fans are a cross-section of the public. A lot of them don't know much about the game, and they certainly in my view think only of themselves, and not of the future of the club.
"Some people, all they do is read the league tables, and that's all there is to the game for them. They're pathetic really."
Herbert wouldn't be drawn on Morgan's comments, or whether they were a distraction as the team prepared for Sunday's match.
"To be honest, I don't read the media and I don't listen to it. We're focused on the football," he said after training on Friday.
"I'm not sure what he said, it's not for me to comment."
Durante was equally circumspect, also maintaining he hadn't read Morgan's comments.
"To be honest, I've been through so much of Gareth talk over the last month that I honestly have completely blocked it out," he said.
"I've been in a pretty tough place with all these comments and having to answer for owners, so I'd rather not say much about that.
"Obviously, the fans are hurting from it. It's never nice to have those comments at you. But as players we've decided we're not going to get involved in that, we're not going to talk about it. The less said, the better for the playing group."
Durante appealed to Phoenix fans to support the team when they most needed it.
"Regardless of what Gareth said, as players we want you guys out there. The Yellow Fever, and everyone involved at the Cake Tin are very important to us, and if we're to get out of this, we kind of need everyone pulling in the same direction."