Millward collapsed and died in his Johannesburg hotel room, apparently of natural causes. He was 58.
At a daily briefing Friday, FIFA spokesman Nicolas Maingot said "let us please think of AP Sports Writer Robert Millward, who as you might know, very sadly passed away yesterday."
He then read the contents of a letter to the AP from Blatter: "I will remember Robert Millward, who was a true connoisseur of sports in general and football in particular. He has always been a dedicated professional who has covered a total number of seven FIFA World Cups."
Maingot then asked journalists to stand for a moment's silence.