Gerrard damaged his hamstring in Saturday's 1-1 draw with Blackburn Rovers.
"Steven will not travel. He has a problem with his hamstring," Benitez told reporters on Tuesday.
"If it was the last game of the season he would play, but with Sunday's game (against Manchester United) coming up it is too much of a risk.
"It is a big loss for us though because Stevie can change games."
Midfielder Momo Sissoko is likely to play despite a calf problem, but Dutch striker Dirk Kuyt is a major doubt with an ankle injury. Striker Robbie Fowler has not travelled to France because of a back injury.
Liverpool top Group C with four points along with PSV Eindhoven.
