"During the premiership we tried to play in a certain style but we had to change our formation against Miramar," he says of the mid-table Capital Premiership side.
What is noticeable is the Wairarapa United-look about the Wellingtonians who have four Argentines in their mix, an Italian and other exotic names such as Janek Chmielewski.
The Argentines are Marcelo Riccardo, Mario Barcia, Justo Montenegro and Facundo Barbero, although Garcia has the headache of dropping one because only three foreign players are allowed in a game.
Riccardo and Barcia are defenders while Montenegro and Barbero, 18, are midfielders.
A striker, Barbero has had to adapt in the engine room but that hasn't stopped the teenager from finding the net.
"Facundo had to wait until he was 18 to play here because Fifa rules don't allow anyone under that age to play unless they are with their family," the coach says, revealing Barbero hasn't lost time catching up with his goal-scoring prowess.
With 21 of their 22-strong squad champing at the bit, Garcia isn't looking forward to revealing who won't play but, nudge- nudge wink-wink, it's no secret the predominantly youthful Island Bay love to employ an attacking brand of football.
"Napier are much better than us so if we stick to our plan we should get the result," he says, comfortable in the knowledge the approach paid dividends against Miramar but mindful it may have been "a fluke".
With several teens in their starting line-up, Garcia believes it's imperative for the Paul Muollo-captained side to play for 90 minutes and yield a winner within regulation time, rather than relying on "the lottery" of extra time and penalty kicks.
Among the youngsters is Stockill who has impressed Garcia after sealing his starting berth at the small club, which boasted eight goalkeepers at the start of the season.
The 18-year-old son of Karen and Adrian Stockill, of Napier, is a first-year commerce student at Victoria University and joined the club on the recommendation of former Kinetic Electrical Hawke's Bay United coach Chris Greatholder.
"Chrissy pretty much sorted it all out for me," says Stockill who receives once-a-week coaching sessions from former All Whites and Bay-born goalkeeper Mark Paston in the capital.
"That's quite cool because Mark went to Napier Boys' [High School] as well."
Stockill has conceded three goals in the cup matches although he missed the first encounter against Wellington United, an away 3-1 victory.
Captain Muollo is their most senior player, having represented the black-and-yellow brigade in their only other cup quarter-final several years ago. Stockill, who has trained with the Rovers (Central League) and Bay United squads, says he exchanged texts with Rovers defender Bayley Chadderton well before their match, aware the sides were on a collision course.
"We knew it was always going to happen."
The Yellow Fever, after watching the EPL matches at the Cake Tin tonight , will be out in droves to support Island Bay tomorrow with "special T-shirts and all sorts".
"We had about 300 people here against Miramar but we're expecting a lot more on Sunday."
His parents, sister Josie, 20, a talented basketballer back home on northern summer holidays from Colgate University in Washington state, and brother Oscar, 16, will be in the crowd.
MATCH DETAILS
WHO: Island Bay United v Napier City Rovers.
WHEN: Tomorrow, 2pm kick off.
WHERE: Wakefield Park, Wellington.
REFEREE: Chris Kerr.
AR1/AR2: Mark Whitehead/Peter Linney.
Bluewater Napier City Rovers: 1 Jonty Underhill (GK), 2 Josh Anstis, 4 Bayley Chadderton, 5 Bill Robertson, 6 Miles John, 7 Matt Hastings, 8 Stu Wilson, 10 Andrija Ilic, 11 Andy Bevin, 12 Oli Chapman, 14 Josh Stevenson, 15 Ryan Tinsley, 16 Danny Wilson (c), 18 Angus Kilkolly, 20 Chris Greatholder, Jarrod Hastings (RGK).
Coach/player: Bill Robertson.
Manager: Malcolm Wilson.
Island Bay Coolmoves: William Stockill (GK), 2 Marcelo Riccardo, 3 James Eadie, 4 Jack Williams, 5 Mario Barcia, 6 Finn Sorger, 7 Justo Montenegro, 8 Ian Paterson, 9 Facundo Barbero, 10 Luciano Colluci, 12 Hayden Flett, 13 Paul Muollo (c), 14 Ruairi Cahill-Fleury, 15 Callum Holmes, 17 Janek Chmielewski, 19 Ronal Prasad, Washington Bgoni (RGK).
Coach: Martin Pereyra Garcia.
Manager: Poasa Tapuna.
ROADS TO QUARTERFINAL
Rovers:
away v Taradale FC, 2-1.
home v Wellington Olympic, 5-4.
home v Palmerston North Marist, 3-3, 5-4 after extra time.
away v Tawa FC, 4-2.
Bay Island:
away v Wellington United, 3-1.
home v Wainuiomata, 1-0.
home v Victoria University, 2-1.
home v Miramar Rangers, 3-2.