Malian referee Koman Coulibaly, the subject of vicious attacks in the US media after disallowing a late goal by USA in their 2-2 draw with Slovenia, could be asked to face FIFA's refereeing committee to explain his decision.
A FIFA source told a US newspaper that Coulibaly could be asked to clarify the reasons for his disallowing the 86th-minute Maurice Edu goal even though there was general confusion for the reasons behind his decision.
USA forward Landon Donovan said: "We asked the ref many times what it was or who it was on and he wouldn't or couldn't explain it. I don't know what to think of the call because I didn't see any foul, just a normal free kick and a goal."
Referees must submit a written report to FIFA after each match, but there is no requirement to explain every decision. FIFA rules state: "On the report form the referee shall note all occurrences such as misconduct of players leading to caution or expulsion, unsporting behaviour by supporters and/or by officials or any other person acting on behalf of an association at the match and any other incident happening before, during and after the match in as much detail as possible."
After the group stage, FIFA assess the performances of all officials and decide which ones to retain for the knockout stage of the tournament.
"If [Coulibaly] is found to have made a serious mistake, especially one that affected the outcome, then he would be highly unlikely to play any further part in the tournament," an unnamed source said. "FIFA is determined to keep refereeing standards high and does not want high-profile mistakes."
Coulibaly, 39, is one of Africa's most experienced referees and has been officiating for 17 years . Earlier this year he refereed the final of the African Cup of Nations between Ghana and Egypt.