I am contemplating heresy. I am starting to wonder whether the Socceroos' best keeper is still Mark Schwarzer.

Don't get me wrong - I've always been a huge fan of Schwarzer. He's flown the flag for Australia in the EPL and has always been available for the Socceroos. He kept Middlesbrough up for donkeys years and then turned Fulham into a top ten and European club. He made those penalty saves against Uruguay (I was right behind the goal!) and has made the difference on countless other occasions for Australia - but how long can it last?

Professional and international football is a cut-throat business after all - devoid of sentiment. No-one would seriously suggest that any player should continue to be picked forever on the basis of reputation, so what are the factors that justify a long term keeper retaining his spot?

Experience
Experience is worth a lot. If you've been there and done that in the World Cup, Asian Cup, EPL and Europa League Final, you might start to get just the merest glimmering of what this keeper caper is all about. Schwarzer's reputation (especially facing penalties) would daunt enemy strikers and would give a manager confidence that he wouldn't be destroyed by big matches and will be able to go out and do it again and again.  

Team confidence
A keeper's contribution to the team effort does not stop with his influence in the box. Almost the biggest part a good keeper plays is to give his team mates confidence that if they screw up it won't be the end of the earth. A confident team is better able to take the calculated risks which are necessary to gain an advantage over an otherwise evenly matched competitor. An outside back won't make that overlapping run to get in behind if he is too worried about the consequences of being caught out of position - especially in professional and international football where judgments about performance mean ongoing selection...or not.

Arsene Wenger wanted Schwarzer, only last (English) summer. The main reason he wanted him was to free up his stultified superstars and get them to reach their full potential. But Fulham are no longer in their rusted-on top ten spot, and may struggle to avoid relegation this season.

Organisation
Schwarzer has always been really active in the organisation of his defences in the past, but as an avid Schwarzer-watcher I've noticed him becoming somewhat less involved in recent times. Could it be because he is unhappy about missing out on that move to Arsenal? Or does he simply have less to say these days?

The goal in the Asian Cup final saw Carney out of position but Schwarzer should have been screaming at him beforehand. Similarly, the goal conceded against Thailand - our left back (McKay?) was caught out but Lucas Neill was ball-watching and Schwarzer should have been letting him know the danger.

It would be fascinating to be a fly on the wall when Osieck and Schwarzer discuss his role and performance. I wouldn't mind betting that communication with the defenders is a major topic of conversation.

Dominance in the box
Team mates love to see their keeper dominating the box - it's a major part of that Team Confidence heading above. Schwarzer has always been a huge, imposing presence but has noticeably become more rooted to his line in recent years - relying on his defenders and his reflexes to defuse dangerous situations.

For me, that is the beginning of the end. What it suggests is a loss of confidence in timing - timing off the line and timing to take crosses and corners is the hardest keeping skill to master and the first one you lose when you're getting past it.

Positioning, reflexes and shot stopping
While timing off the line is the first skill you lose with age, positioning and shot stopping are the last. Until fairly recently, I would have said that Schwarzer was still very strong in this area. He's still incredibly good, but is he better than our other options?

Is he better than Fulham's other options?

It's not just the recent howlers that worry me - it's the consistent pattern of errors and goals flying in that I'd normally expect him to save that are starting to raise eyebrows - and not just mine.

The most important question, which Osieck must ask himself every time he sits down to pick a team, is: is Mark Schwarzer better than Adam Federici, Nathan Coe, Mitch Langerak et al?

Despite having little to do, Federici had a blinder against Oman and I felt my own confidence surge. How much more must the confidence of the players on the pitch have been bolstered by Federici's commanding presence in the air and fantastic save from a set piece when badly unsighted?

Of course, one save does not an international superstar make. All of the above factors need to be taken into account (and probably a few more that a tall-poppy cutter like me doesn't know about), and on balance Schwarzer - arguably the greatest ever servant to Australian football - probably keeps his place.

For now.

As a footnote to the above point regarding Schwarzer's physical presence, I walked past him a couple of months back in Portsmouth - looking tall, fit and utterly unapproachable.

"Go and get his autograph!" said my wife (Kazzie), but as I watched him stride away towards Horatio Nelson's flagship (HMS Victory), I admonished her that you don't hassle superstars in public.

Except in writing.

From a safe distance.

Adrian Deans is the author of Mr Cleansheets - published by Vulgar Press, distributed by Dennis Jones and Associates and available in all good book stores and in ebook form on www.mrcleansheets.com