In his column for the Daily Mail, Keown explained: "There was talk after John Terry's back surgery in 2006 that he had lost some mobility and that was underlined against Tottenham.
"He looked uncomfortable against the small, tricky Jermain Defoe on the edge of the box in the first half. Lacking pace, Terry has to get to work early, as he cannot recover like other defenders.
"Terry's exposure like that may spell trouble for the World Cup, where there will be plenty of fast, short players with low centres of gravity. To defend at international level, you need blistering pace. When I faced Romario and Ronaldo against Brazil, they were faster than lightning and stopped as if they had ABS brakes."