Until earlier this week, cashed up CSL clubs were able to recruit five foreigners, one of whom had to be a player from the Asian Football Confederation, the so called "4+1 rule".

But that has now been scrapped under what is reportedly government pressure.

Big-spending Chinese teams, who have been splashing eyewatering amounts on leading European or South American players, will now be able to sign five foreigners of any nationality, but only allow three on the pitch at any one time. In the past they could field three non Asian players alongside one Australian (or other Asian player).

The move is said to be sanctioned from high levels although clubs have reacted angrily to the initiative as it has been sprung on them in the midst of the January transfer window, when in recent years they have been aggressive spenders.

The changes – particularly the one about only playing three foreigners at once – have been implemented to force clubs to invest and develop more local talent.

The +1 Asian Confederation loophole had allowed many Australians to find a niche in the developing Chinese market.

But logic dictates that if they are now able to sign five players from anywhere, the super rich Chinese clubs will flex their muscles even more in the major European markets rather than worry about recruiting an Australian as an Asian signing.

The only chance most Australian players will now get is if they are signed as one of the two foreigners who are not first choice players – although that means they will probably spend much of their time on the bench.

The problem is particularly acute for those hoping to move to China in this particular transfer window.

Socceroo Robbie Kruse and his Melbourne based agent, John Grimaud, are currently in China where they were hoping to tie up a deal with Liaoning Whowin. Adelaide's James Holland, a former Socceroo midfielder, was also in talks with the same club.

Speaking from China on Tuesday, Grimaud said: "The clubs are not happy at the timing of this and the way it has been implemented in the middle of the transfer window".

"It is making all the deals for Australians much harder now. If they can only play three at once, it is more difficult for players to find a spot where they can be one of the three always considered likely starters.

"It's going to make it much more difficult for Australians now."

Kruse was hoping to reactivate his career after injuries curtailed his game time with leading Bundesliga club Bayer Leverkusen. If he doesn't move to China he would, however, have other options, with clubs in the Middle East and Europe having shown interest in the talented attacker.

Other Australians, like Trent Sainsbury, have long term contracts with CSL club Jiansu Suning but the three-player rule may impact on his game time.

Lou Sticca is another leading Melbourne-based player agent who has dealt with CSL clubs for many years – long before the current goldrush began.

He says, unequivocally, that "it's going to get a lot harder and the pathway will dry up for many now".

"If Chinese clubs are only going to be able to play three foreigners then they will go out and get the very best they can.

"Australian players will face difficulties, but I still see it as a market reaction. I don't think that the crazy money that has been spent in recent times is sustainable so it will be a bit tighter.

"The reality is that if Australians are good enough they will get offers to go there still.

"The demand for Australians is primarily for defenders, so good defenders will probably still get the chance to go up there. The big Chinese clubs will spend their huge money on midfielders and strikers, the players who make a real difference, but there may be opportunities for defenders," Sticca says.

There could be some upside for A-League clubs who might be able to hold on to some of their hotter prospects if it is so much harder to break into China, but clubs in the Middle East and other Asian markets will still likely pursue leading Australian prospects.

Incidentally, Football Federation Australia has confirmed the A-League will implement the 4+1 rule from the 2018-19 season onwards.