In particular, the rods supporting a central video screen cube during the England v Paraguay game cast a pattern of shadows across the pitch, prompting UK rights-holder the BBC to apologise to viewers.
FIFA spokesman Markus Siegler adds: “If you have watched the matches on Saturday on television, you saw that for the matches in the afternoon - when the sun is shining – is not the best for TV pictures.
“We are assessing the situation and understand that it is not nice for the millions watching when there is such a distraction with the shadows.”
However, with temperatures soaring, there is a concern for player welfare if roofs are closed.
FIFA chiefs are likely to close the roof of certain upcoming World Cup games – to help prevent the shadows which left many TV broadcasters complaining.
