"It all comes down to the pace he's got,'' said Butler. "He's just two yards quicker than most defenders that we come up against. And if teams are successful in shutting him down, they often use too many players to do it, which allows us to exploit the extra space. It's a win-win for us, really.''
After winning the ASB Premiership golden boot last season, Krishna has become the hottest property in the domestic game and been linked with a move to Auckland City for their Fifa Club World Cup campaign in Morocco in December.
One man who knows Waitakere's threat better than anyone is Melville defender Aaron Scott, who has shared a changing room with Krishna, Butler and Myers for the past five seasons at United.
Scott said there is a big difference between being aware of Krishna's threat, and being able to stop him.
"Roy has that x-factor,'' Scott said. "If you give him the ball and he's got time and the opportunity, he can do things with it. And not many players have that - especially domestically.
"If he has the ball anywhere in our half he can turn, beat a defender and shoot off either foot. It's something we have to be aware of.''
But Scott is filled with confidence by a back four that has helped make Gower Park a fortress this season. Melville have not lost a game at home all year and Scott credits the teams stability to the work ethic inspired by their 35-year old left back Gavin Douglas, who made the Cup final with the club in 2003.
"Gav is like Benjamin Button, he just keeps getting younger,'' Scott said. ``Much like fine wine he gets better with age too. He'll put in a shift.''
In the other semifinal in Christchurch, Wellington Olympic will travel to face Cashmere Technical, with both sides still harbouring dreams of doing the `double'.
Riding a 14-match unbeaten run in all competitions, Cashmere have already clinched the Mainland Premier League title and are confident of reaching the final for the first time in the club's history.
But standing in their way is an Olympic squad full of experience, with six members of the side that won the Cup in 2009 still in Mick Wait's team.
Olympic can still win the Central League, too, but face the uphill challenge of having to beat Petone by four goals in the last game of the season.
Melville United v Waitakere City
Gower Park, Hamilton
Saturday 24 August, 2pm
#MELvWTK
Cashmere Technical v Wellington Olympic
Garrick Memorial Park, Christchurch
Saturday 24 August, 2pm