The former Socceroo told au.fourfourtwo.com that the future should always be planned for, particularly when such an opportunity comes along.

"When in three or four years when we look back and complain there are no youngsters coming through...I mean when are you supposed to try them out?" he asked.

"I got a chance [in the Socceroos] because Mehmed Durakovic was injured. Some of those boys the other night got a chance because some of the other boys were rested. That's how it works.

"Some will make the most of it and some won't.

Popovic made his Socceroo debut in 1995. He played alongside veterans Alex Tobin, Tony Vidmar and Milan Ivanovic in a 0-0 draw with Columbia in Brisbane.

Tobin said publicly this week that young Socceroos should be brought into the team alongside more experienced players. Popovic believed it wasn't an issue.

"We qualified, that's the most important thing," added the former Crystal Palace skipper. "What he [Pim Verbeek] chooses to do after that in my opinion doesn't really matter.

"Maybe the public will feel a little bit let down but you've got to blood these youngsters somewhere."

Meanwhile, Popovic, is adjusting well to the long A-League off season, he said.

"It's been eight weeks. The coaching staff have structured a good pre-season for us. It's a long pre-season, and I was a bit worried at the start, I've never done one so long compared to Europe.

"But the coaching staff have had a lot of experience with it so they mix up training. We've been having the weekends off just to refresh but now we're playing games, it's all exciting now.

"The priority is the A-League, there is no doubt about that. If we can win something before it, then that's a bonus, but the key is to be prepared for that first game."

Meanwhile new Sydney FC signing Simon Colosimo added that Wednesday night's training match against Blacktown Demons was "weird".

"We haven't had a kick on a big pitch against another team in a while, so it was good to get out there," he said.

"We were pretty patchy but there were some good things and I'm sure we'll improve on that in the next couple of weeks. It felt a bit weird."

It was Sydney FC's fifth training session this week.

Colosimo, 29, said just getting back into an 11 v 11 situation took some getting used to.

"It's more just a matter of running around on a big pitch against guys wearing a different colour," he said.

"In training you can simulate that, but it's not the same."

And the former Perth Glory skipper joked that if singer Brian McFadden played again in the pre-season for Sydney, "we may put him under some pressure because we'll want to get some results."