Graham Poll may have refereed his last World Cup match after a series of high-profile errors during Croatia's turbulent game against Australia.
The English official booked Croatia's Josip Simunic three times before sending him off and also twice waved away strong Australian penalty claims.

Fifa will study Poll's performance and he will learn his fate by the weekend.

But Fifa president Sepp Blatter said: "We had four officials and what is not understandable is nobody intervened."

He added: "I'm not surprised about the reaction. There are people there and one of them should have intervened and run on to the field and said, 'Stop, stop.'

"That's why they have the communication system. The assistants and the fourth official have the right to call on the referee and tell him. It is not understandable how this happened."

But Blatter stopped short of saying Poll would definitely be sent home: "I place my trust in the referees' committee. I think they have enough tact to deal with this case.

"We should not forget that Graham Poll in his previous matches achieved fantastic things.

"Of course, we cannot excuse it but we should understand it. Referees are human beings and human beings make errors."

A Fifa statement read: "We had a first in the history of the World Cup when a player received three yellow cards - this is a little bit too much."

Before the tournament, Fifa warned referees they face being sent home if they underperform.

Poll has said he expected to be shown no mercy if errors were made - either by himself or his assistant referees Philip Sharp and Glenn Turner.

"If you make a big mistake it will be your last game. There is a very high standard of performance expected of us," he said.

The Tring official had been tipped by many to be in the running for the final but he will now be expecting the worst.

Blatter made it clear that Fifa would not tolerate the sort of mistakes that plagued the 2002 tournament in Japan and South Korea.

And Poll, 42, was never far away from controversy during Thursday night's Group F showdown.

He awarded the Socceroos a first-half penalty for handball by Stjepan Tomas but failed to spot an even more blatant handball by the same player after the break.

Mark Viduka also seemed to be bundled to the ground in the box during the first half, while it appeared that Harry Kewell was offside when he scored Australia's second equaliser.

Poll, who also sent off Australia's Brett Emerton and Croatia's Dario Simic for two bookable offences, then failed to dismiss Simunic despite booking him twice.

It was only after the final whistle when he brandished a third yellow card at the centre-half that Simunic finally got his marching orders.

Viduka said: "I was sure it was his second yellow card. I asked Graham how many cards had Simunic received. Graham said only one. It looks like he got it wrong."

Despite the errors, Viduka hopes Poll is not axed.

"Everybody makes mistakes," said the frontman. "Graham Poll is a top quality referee. I will not say anything against him."

Poll took charge of the Togo against South Korea game and also officiated Saudi Arabia's clash with Ukraine.

England captain David Beckham also gave his backing to Poll.

"Graham Poll is a very good referee - everybody makes mistakes," Beckham said.

"He's a nice person as well and one of the best referees in England."