BOXBOROUGH – Five years ago, Brian Fontas was scrambling to find players to fill out the roster for his Acton-Boxboro Regional girls’ hockey program.

In particular, a goalie to put between the pipes.

The school was granted a waiver that allowed seventh and eighth graders to participate, opening up an opportunity for 12-year-old Cali Loblundo.

The seventh grader seized the position and helped A-B to an appearance in the 2011 Division 1 state championship game, a 3-1 loss to Hingham.

A year later, eighth grader Melissa Bambery joined the fray and a robust goaltending combination was born.

“When Melissa joined the team it was kind of like, ‘Who is this girl?,’’’ said Loblundo, who has been on skates since she could walk.

“But ever since we’ve been really good friends . . . we’re such good friends. We learn from each other. When the other one is down, we pick each other up. It’s great to have someone that knows what you’re going through because goalie is such a unique position.’’

To many, it is hockey’s most important position and Fontas has had the luxury of building from the net out for the six seasons, a stretch that includes two state final appearances — the Colonials fell to Reading, 3-0, in the title game last March — a semifinal, and two quarterfinals.

Bambery and Loblundo, both now seniors, have formed the backbone of that remarkable run.

“I almost take [them] for granted,’’ said Fontas. “And I think when they’re gone next year it’s really gonna hit me. I’ve been so lucky to have these two kids for six years.’’

Fontas does not have a set rotation, instead relying on feel to determine a starter. Last season, Loblundo (1.71 goals against average, .924 save percentage) started 12 games and Bambery (1.10, .928) nine. Through three games this year — all shutouts — Loblundo has started two and Bambery one.

Loblundo, whose brother Andrew was a goalie for the A-B boys’ program from 2008-12, has started every postseason game during her high school career.

“[Loblundo] is my go-to goalie in the playoffs,’’ said Fontas, who guided A-B to an 18-4-3 record last season. “I’m not saying Melissa’s not a good goalie; as a coach, you’ve got to go with the kid you think might be a little hotter at that time.’’

And that’s just fine with Bambery. The two knew little about each other before hockey brought them together, but ‘The G’s,’ as they call themselves, have since formed a strong bond because of the position they share.

“We always support each other on and off the ice,’’ said Bambery. “We cheer for each other . . . when Cali is in net and the puck’s in the other end, I’ll be cheering for her and she’ll wink at me or acknowledge that I’m cheering for her when she’s not getting any action.’’

Like A-B, Medfield High also has a strong goaltending tandem in freshman Sophia Merageas and sophomore Skylar Flynn.

Flynn was a key contributor to the Warriors’ postseason run a year ago, but is playing less this year because of the emergence of Merageas.

First-year coach Michael Cox , a goalie at Merrimack College from 1989-93 who has coached at the collegiate level (Harvard, Northeastern, Boston College, and Salve Regina), believes Merageas is a lock to play at the college level.

“I’m new to high school hockey, so I haven’t seen all the goalies, but I’ve been around hockey and goaltending a long time . . . she certainly appears to be one of the top netminders in high school hockey,’’ he said.

“She’s got all the ingredients to be an elite goaltender. I think she has the potential to be a Division 1 goalie. I think she could start for a Division 3 college team tomorrow.’’

But when Merageas needs a breather, Cox will not hesitate to turn to Flynn. And in a pinch, he could go with sophomore Caroline Davenport, who was Flynn’s backup last season but decided to skate as a center this season.

“To go anywhere you have to have a goaltender,’’ said Cox, whose team has allowed four goals through five games this season. “You can be short a defenseman or a center . . . but if you’ve got a goaltender you’ve got a chance.

“It’s nice having not just one, but two goaltenders, who right now don’t need a lot of instruction and I can focus my time and energy in other areas.’’

At Arlington Catholic, junior Jasmine Mucci is in her first season as the starter after sharing time with Katherine Crane last season.

“Jaz is an important piece of the AC girls hockey puzzle,’’ said Arlington Catholic coach Maggie Taverna. Mucci registered seven shutouts in nine games last season.

“We have a great defensive corps, but every team needs a goalie to make saves when the ‘D’ makes mistakes . . . Jaz thrives from making saves.’’

With Bambery and Loblundo, Fontas knows what it’s like to have goalies that thrive in the crease. And he would like nothing more than to send his ace goaltending duo off with what has proven to be an elusive state title.

“We wouldn’t be the program that we have been in the last six years without both of those kids,’’ said Fontas. “I owe a lot to both of them.’’

Eric Russo can be reached at at eric.russo@globe.com.