"It's not about blooding youngsters, it's up to them to earn a spot.''
Rufer is a particularly intriguing prospect and has only experienced five minutes of A-League action this year when the 17-year-old got on the paddock against the Newcastle Jets on the road in round 18.
Merrick's hand may be slightly forced against Sydney though with Manny Muscat suspended after he picked up his eighth booking of the season against Adelaide.
Muscat was one of eight players shown a yellow card across both sides during yesterday's dour affair, which was settled from the penalty spot when Adelaide's Marcelo Carrusca provided a deft finish in the 58th minute after Andrew Durante had fouled Tarek Elrich in the box.
There are more injury worries for Merrick with Ben Sigmund (thigh muscle) and Vince Lia (groin) both experiencing pain yesterday, although there was no definitive diagnosis on them after the game.
"Both of them wanted to stay on and they battled their way through,'' Merrick said.
Injuries have been a concern all season for the Phoenix and their mounting toll has been one of the major reasons behind their late-season woes after they seemed assured of a finals spot when they were running hot in January.
"Our best 11 would match it with anyone, we've proved that,'' Merrick lamented.
The high injury count has meant an extended run in the starting side for midfielder Matthew Ridenton and the teenager has continued to show improvement during the past couple of months.
Ridenton was one of Wellington's better-performed players during the loss to Adelaide, which proved a contest with few highlights.
"I thought our boys fought very hard,'' Merrick said. "It was a game of few chances at each end.''
Aside from the penalty, the most clear-cut opportunity of the game fell to Phoenix striker Stein Huysegems but with the goal at his mercy and just the keeper to beat he only produced a weak effort at the end of the first half, which was well-saved by Eugene Galekovic.
Had the Phoenix gone ahead there, yesterday's result may have been different but like so many of their games this season they were left to ponder another result that got away.