His work in the second half of the crucial Group H match between Ukraine and Tunisia was publicly criticized. Amarilla was not chosen to officiate Knockout Round matches.
He was the referee in the first qualifying match for the 2010 World Cup between Colombia and Brazil (October 14, 2007).
He was preselected as a referee for the 2010 FIFA World Cup. Amarilla was chosen to officiate at the finals, but was withdrawn following the failure of a fitness test by his assistant referees.
On September 11, 2012, he officiated a 2014 FIFA World Cup qualifying match between Uruguay and Ecuador. He was heavily criticized after not giving a clear penalty to Ecuador, robbing them of a historical win in the Estadio Centenario.