The skilful playmaker, who turns 25 on Tuesday, points out Auckland City hadn't lost a game last season until the final against Team Wellington.
"Obviously the whole league stood up and took notice," says Halpin who is returning to the Bay franchise "because of the new faces around the team ... and a few old ones but mainly the new".
The Finlay Milne-captained side were "gutted" in March to have missed out on a historic O-League berth after a semifinal loss in Napier to Team Wellington, who defied the odds to become the 2015-16 premiership champions.
Team Wellington, who had lost 2-0 to Bay United in the capital a few days earlier, ended Auckland City's 28-game unbeaten run with a 4-2 result in the grand final at Albany.
Had City prevailed, the Bay United would have created history in gaining entry to the O-League by virtue of finishing second on the ASB Premiership ladder.
The Bay had still improved on four seasons of incrementally finishing higher to claim the second rung for the first time after the round-robin phase as well becoming the best Bay franchise team to score the most points.
Halpin says he started with a hiss and roar with Wellington last summer, scoring a winning goal in their first match but ankle and hamstring injuries plagued his progress, including his campaign with Napier City Rovers in the Central League over winter.
"I'm feeling good now and training hard so touch wood," he says, revealing Angell was tweaking their systems after warm-up games - a 2-0 win over the Phoenix Reserves in Palmerston North last Saturday and a 3-0 loss to Team Wellington the Saturday before.
He hopes to start on Monday but, failing that, will be getting behind the lads.
"All the lads are buzzing," says the player whose father Russell Halpin will be here for six weeks during Christmas to watch him play.
The other comeback kid from Wellington is wing back Fergus Neil, who had a summer with WaiBOP United after a five-season stint with Bay United.
"I'm really excited to be back because I've not played with Brett before," says the 24-year-old Napier-born who is keen to "give it another crack with the Black and Whites".
"He knows a lot about the game and is a really good coach and will probably make a difference to my game."
It wasn't easy for Neil who pondered which club to sign for but sacrificed O-League to help his home franchise create history.
As a "wide defender" Neil sees the scope to roam up front when the opportunities arise.
The team culture is great and everyone was feeding off each other.
"All the boys are getting on really well so it's an important thing off the field for everything to fall into place in good symmetry."
It was freezing in Wellington so Neil is relishing returning to the Bay which is bathed with sunshine most times.
Nevertheless, he believes he has evolved into a better player having played in different parts of the countries with different clubs and under different coaches.
"If you don't go out then you don;t grow so all the clubs are a good experience."
Other new faces include Ben Everson (England), Alex Palezevic (NZ age-group), Facundo Barbero (Argentina), Matthew Whatley (Wales) and Nile Walwyn, (Canada).
Neil says some of the overseas signings have travelled globally so learning off them here is equally important.
He is now settled in Napier with partner Izzy, 22, and has a 1-year-old stepson, Arlo.
Apportioning time and energy to family and football is a new challenge for the affable player.
"You have to more time for life here than just playing football," he says, after Bay United launched their season with a dinner night at the Bluewater Hotel restaurant in Ahuriri last Saturday night.
Neil is in his first year of pursuing a primary school teaching degree through the Eastern Institute of Technology.
BOTH TEAMS
HAWKE'S BAY UTD: 1 Josh Hill (GK), 2 Sean Liddicoat, 3 Kohei Matsumoto, 4. Finlay Milne (c), 5 Mathew Whatley, 6 Alex Palezevic, 7 Cory Chettleburgh, 9 Facundo Barbero, 10 Sam Mason-Smith, 11 Saul Halpin, 12 Ross Willox, 13 Ethan Dent, 14 Martin Canales, 15 Ben Everson, 18 Lewis Tiller, 19 Nile Walwyn, 26 Ruben Parker Hanks (RGK).
Coach: Brett Angell.
Ast coach: Jamie Dunning.
Manager: Malcom Wilson.
GK coach: Kyle Baxter.
Physiotherapist: Aaron Shirley.
Strength & conditioning: Brandon Campbell.
Video analyst: Tim Motu.
WAITAKERE UTD: 1 Pirmin Strasser (GK), 2 Scott Hilliar, 3 Steart MacKay, 5 Julyn Collett, 6 Harrison Nash, 7 Stefan Thelen, 8 Ryan Tinsley, 9 Dylan Stansfield, 10 Eder Franchini Pasten, 11 Ian Hogg, 12 Dan Morgan, 13 Ryan Cain, 14 David Parkinson, 15 David Icardo Hernandez, 16 Dylan Manickum, 17 Jake Butler, 19 Tom Shaw, 20 Keegan Linderboom, 21 Abdulla Al-Kalisy, 22 Lewis Caunter, 23 Jake Porter, 28 Liam Anderson (RGK).
Coach: Chris Milich.
Ast coach: Carl Jorgensen.
GK coach: Ross Nicholson.
Manager: Grant Robertson.