The former Olyroos and Socceroos boss has been courted by several clubs at home and overseas since joining the A-League and snaring Premiership and Championship titles.
 
But he was dismayed by the attitude shown by the Mariners UK sister club Sheffiield United which has now prompted him to speak out - and advise Australian players to steer clear of the lower English leagues.
 
'I had a video conference with three directors and [football director] Dave Bassett, and to be honest I was shocked with what I heard,'' Arnold told the official FFA website.
 
''When I started talking about how I liked to play out from the back, it became clear pretty quickly that wasn't the way they thought football should be played.
 
"Sheffield United are a big club, with big support, but I couldn't see myself progressing in that kind of environment.
 
''What it showed me is that our football here has advanced a lot further, and a lot quicker, than we tend to appreciate. I've been as guilty as anyone of underestimating our league.
 
"The whole experience has taught me something, that's for sure."
 
He added: ''While I've made it clear I have ambitions to go overseas, I also have the ambition to go somewhere where there is a good philosophy, where the league is building.
 
"I didn't see that at Sheffield United.
 
''After what I've heard, I would say to any player, any agent, even parents, don't go there. 'Playing in the English lower leagues is not going to improve your game.''