Wellington Phoenix head coach Ernie Merrick shrugged off his side's 5-1 thrashing at the hands of Melbourne City in the Westfield FFA Cup Round of 16 saying it was an inevitable consequence of his team's demanding pre-season schedule.

"We had a few injuries and we had five 19-year-olds on the field tonight and it showed," he told reporters after the game at AAMI Park.

"I think it was fatigue and experience. But that's part of pre-season. I'm not concerned by it in the slightest.

"I saw a few things that I wanted to see from our youngsters who are amateur players. Some of them really stood up. If anything a couple of the senior players let us down a little bit."

For City, a suspected hamstring strain suffered by star forward Harry Novillo was the only blemish for Melbourne City on Wednesday night.

Penalties from Aaron Mooy and Bruno Fornaroli, together with goals from Novillo, Robert Koren and Wade Dekker sealed a berth in the FFA Cup quarter-finals for the home team, who completely outclassed their A-League rivals from the New Zealand at AAMI Park.

Wellington meanwhile will be sick of the sight of City after being knocked out of the A-League finals by van 't Schip's men on home soil in May.

Novillo though, who signed a two-year deal in June after impressing as Damien Duff's injury replacement last season, has now joined City's lengthy ranks of walking wounded.

"Harry's the disappointment, actually," van 't Schip said following the former Lyon winger's withdrawal in the first half.

"He probably is injured. What he exactly has we don't know. He felt something. We'll have scans and see what comes out of that.

"Hopefully it's not something too big. He's an important player for us. He's threatening, linking up, dangerous, has a great finish. We just have to wait."