The New Zealand club are three points in front of Newcastle Jets heading into the final match of the season and need just a draw against bottom-of-the-table North Queensland Fury on Sunday to ensure their spot in the top six.
The Jets kept themselves alive with a 4-0 hammering of Perth Glory last night making the maths simple for the Phoenix.
"It's quite an easy equation - get a point and you're through," Herbert said.
"They'll be a tough opposition for us but at the end of the day we need a point and if we're good enough we'll get it."
As the Phoenix take on the Fury at Westpac Stadium, the Jets have the unenviable task of traveling down the F3 to take on Central Coast Mariners who have not lost in eight matches.