Football's rule-makers are set to approve more experiments with goal-line technology on Saturday, but time is running out to introduce it at the 2014 World Cup and prevent wrong decisions infuriating fans and players.
High-profile mistakes by referees at last year's tournament led to FIFA President Sepp Blatter reversing his long-held opposition to officials using high-tech aids to assist in decision-making.
But 10 systems investigated by FIFA last month all failed stringent tests, preventing the International Football Association Board on Saturday from approving trials in real games.
FIFA general secretary Jerome Valcke told The Associated Press there should be "additional tests in the future, at least until 2012, to see if it works."
But FIFA is in a race against time to implement the technology in Brazil's stadiums by 2014 to prevent teams like England and Mexico complaining again about disputed goals leading to them being eliminated.
It will have taken almost three years of trials to get to the stage on Saturday when IFAB can approve UEFA's conservative alternative of using extra manpower to rule on disputed goals at the 2012 European Championship.
The use of an additional referee's assistant behind each goal is still only in its second season being tested in the Europa League.
Football has previously steadfastly refused to make changes while major sports including tennis, American football, baseball and ice hockey have employed video replay and other high-tech gadgets to help officials get calls right.
Any changes to football's rules must be made by the 125-year-old IFAB which comprises officials from England, Northern Ireland, Scotland and Wales, who each have a vote and FIFA, which has four. Six votes are required for motions to be passed.
The Welsh and Northern Irish backed FIFA last year by voting to keep technology out of the game, with Valcke saying: "We should trust and keep football as a human game."
But Wales manager Gary Speed has provided an indication that the Welsh Football Association will be more supportive of non-human intervention at this year's meeting amid concerns within the organization about the pressure on referees.
"If the referee gets alerted, they can stop it straight away (and say) that it was a goal, then that's fine," Speed told Sky Sports. "I think it's time we went that way. You can't put the onus on officials any more. For an official to give that, they have to be 100 percent sure it's in. If not, they can't give it. That takes it away from them.
"Hopefully it would make them perform better and be more relaxed in the job. We want the right decision."
While there are concerns that football would no longer have the same rules at every level, Speed pointed to how other sports have successfully implemented systems to eradicate errors by officials.
"It works in other sports, like cricket and rugby, and they don't have that at local level," Speed said. "I think there could be a trial period brought in on certain situations, like the Europa League. They can trial it to see if it's a success."
The errors that created a worldwide furor and put pressure on FIFA came in the first knockout round at the 2010 World Cup.
England was denied a clear goal when Frank Lampard's shot bounced down from the crossbar over the goal line. That would have levelled the match against Germany at 2-2. Germany advanced 4-1. Argentina led 1-0 against Mexico when Carlos Tevez scored while clearly offside. Argentina won 3-1.
The IFAB meetings on Friday and Saturday are being held at Celtic Manor in Wales, which was the site of Europe's Ryder Cup victory over the United States last year.
In other proposed rule changes, FIFA wants referees to be required to stop matches and restart with a dropped ball if stray objects, including an extra ball or animal, appear on the pitch.
Sunderland was able to score its notorious "beach ball" goal to beat Liverpool in a Premier League match in October 2009 when a shot by Darren Bent deflected off the object into the goal, having been thrown onto the field by a Liverpool fan.
Another change could see players banned from wearing neck-warming snoods. FIFA is concerned that the loose-fitting neck scarves could be a safety risk if a player was running through on goal and an opponent grabbed his snood.