Main men were all too tired in South Africa...
Houllier, now technical director at the French Football Federation, thinks that many of the Three Lions' star names failed to live up to their billing, but has focused on Rooney as the most obvious example.
"Probably the key to understanding why England didn't perform at the World Cup is that the top players didn't do as well as we could expect them to," the Frenchman said, according to The Daily Telegraph.
"I'm thinking mainly about Wayne Rooney. He's an outstanding player but whether he was tired or wasn't in good shape I don't know. If Rooney, who for me is a top player and finisher, had scored a few more goals maybe...
"If you look at the teams with one or two top finishers – Germany, Holland or Spain – they usually go forward. Uruguay went so far because of Diego Forlan."
Houllier also believes that it is time that the Premier League considered introducing a winter break to help English players perform better at major tournaments.
"Of the teams that reached the semi-finals, Germany, Holland and Spain had a break of at least two weeks over the Christmas period or new year," he added.