Though convinced that Ryan, 30, will be difficult to dislodge in the near term, Schwarzer - who won 109 caps for his country - views Maynard-Brewer as his most likely ultimate successor.

The West Australian has made six appearances for the mid-table League One London club so far this season, and two more in the League Cup.

The second of those came in last week’s 3-0 quarter-final loss to Manchester United at Old Trafford, after he’d saved a penalty in the shootout win over Brighton in the previous round.

Maynard-Brewer has started in every game in which he’s been available since new boss Dean Holden took charge at the Valley just before Christmas, and Schwarzer shares his faith in the 23-year-old former Olyroo who has been with the Addicks since he was 14.

“Ashley is one we need to keep an eye for the future - I really like what I’ve seen from him,” Schwarzer told FTBL.

“He had a spell in Scotland on loan at Ross County and did well, and he’s now getting the opportunity at Charlton where I think the ultimate plan has always been to make him the number one.

“He’s certainly making a strong claim for that role, and he’s one I think will be up there among the next generation of keepers (knocking on the Socceroos door).

“I think Maty still has plenty more to give and remember he’s only 30, but it’s important for there to be others pushing on and putting their hands up, and it’s good to see Ashley making the progress he has this season.”

Ryan, meanwhile, last week joined Dutch title-chasers AZ Alkmaar after a brief spell at FC Copenhagen, a move Schwarzer roundly endorsed.

“They’re a very good side and are always competing for European places - their style of football will really suit Maty,” he added.

“I’ve been in touch with him and the most refreshing thing for him is that he feels very much wanted. He’ll be the number one and given the opportunity, and that’s what he was seeking.

“When you’ve had a few of seasons like Maty has (at Brighton, Real Sociedad and Copenhagen) where he’s been in and out of the side, that’s always tough.

“I think he’s found a place where they’ve signed him as their first choice and they’re as excited to have him as he’s excited to be there.”

Ryan was one of Australia’s most adept performers during their uplifting run to the last 16 in Qatar, where only an uncharacteristic goal-gifting gaffe against Argentina blotted his copybook.

“I thought Maty did very well at the World Cup. Even more so when you consider how little game time he’s had over the past 12 months," said Schwarzer.

“I thought the mental strength he showed to perform at that level was outstanding. Yes, he made a mistake against Argentina but for me it was uncharacteristic.

“When you play out from the back there’s always a risk, and the more you do it the bigger the risk. At that level you get punished for the smallest of mistakes.