Ian Baraclough feels the call-up of Accrington striker Dion Charles shows he is willing to look "outside the box" but the Northern Ireland manager expects his established core to stick around for some time to come.
The 25-year-old Charles has earned his maiden call-up for this month's World Cup qualifiers against Italy and Bulgaria and the friendly against the United States after scoring 17 goals in 38 appearances for Stanley this season.
"It shows if players are playing regularly for their club and they are in form and performing, they will get noticed," Baraclough said of the decision.
"I've spoken to Dion's agent quite a few times in the last year and he's certainly been pushing his cause.
"I think now is the right time to bring him in. No one is a shoo-in for this squad and the players need to realise that.
"The more players who are performing at certain levels, they will get noticed and get their chance.
"It's certainly not a closed shop."
But while Baraclough is keeping an open mind, he said incoming players would need to show they were worthy of a place at the expense of the tried and trusted group who have been a part of Northern Ireland's recent successes.
There were fears of a rash of international retirements after Northern Ireland missed out on a place at this summer's postponed Euro 2020 finals, but instead Baraclough has been able to call on the likes of Steven Davis, Jonny Evans, Craig Cathcart and Kyle Lafferty once again.
"We're not in a position where we can overlook older players," Baraclough said. "I don't think we can afford to do that as nation.
"It's fantastic to have that level of experience to fall back on, but if they weren't playing at a certain level then they wouldn't be in the squad.
"I have talked about bringing younger players into the squad and I have talked about evolving this squad, because we want to have longevity and success. But if I bring players in, I think it's important that they are worthy of a place in the squad.
"They have to be playing regularly for their clubs and they have to be hitting a high level of consistency. If younger players aren't better than what's already in the squad then they don't deserve to be in the squad."
Davis, 36, had an obvious reason to return as the Rangers midfielder can eclipse Peter Shilton's British record of 125 caps in the next fortnight, but Baraclough said he felt that both he and the other senior players have plenty more to give.
"Yes, we do have a number of players over 30 and some people have written them off, but I don't think that's right," he said. "As long as those players can attain a high level then they deserve to be in the squad."
Since reaching Euro 2016 Northern Ireland have seen two qualifying campaigns thwarted at the play-off stage.
They begin another uphill slog against the odds in Parma on March 25, but are well used to being the underdogs.
"There's nothing better than stuffing people's words back in their mouths, is there?" Baraclough said.
"That's something we will enjoy doing and this squad has done it time and time again.
"Despite being written off, they seem to come back stronger and we will keep going to the well.
"It's important the new players have that mentality as well and we maintain the levels we have done."
