The Spaniard's injury, which the Reds claim is a hamstring problem, puts a disgruntled Djibril Cissé firmly in the spotlight.
Cissé complained that he was being touted around Europe in the transfer window, but manager Rafael Benitez dismissed those suggestions and now clearly expects him to knuckle down as Liverpool's injury crisis worsens.
Benitez said: "Cissé knows what he has to do for us, work hard, try to score goals and stay fit all season. And not to let other things distract him. The rumours about Cissé were already going around long before we beat CSKA Moscow in the Super Cup last week, and he still managed to score two goals for us that night."
Now Cissé will get his chance to play as Liverpool's main front man, probably alongside Peter Crouch, the partnership which has so far this term looked Liverpool's most productive.
The height and awkwardness of the former Southampton man has complemented the pace and movement of Cissé.
Morientes, whose form has been patchy to say the least this term, missed Spain's World Cup game with Serbia and Montenegro this week and is out of Liverpool's trip to Tottenham on Saturday - their first Premiership game in three weeks.
Liverpool insist his injury is a hamstring problem, not a thigh strain, and are awaiting scan results on the seriousness of the problem.
A hamstring strain can take a minimum of three weeks to clear up while a tear will put a player out for as much as six weeks.
Whatever the final report says, and that is not expected now until tomorrow, Morientes faces a long spell out and that opens the door for Cissé to stake his claim.
It is anything but ideal for Benitez, who during the summer transfer window made some dramatic decisions about his strike force.
Benitez sold last season's top scorer Milan Baros to Aston Villa, sent youngster Anthony Le Tallec out on a season-long loan to Sunderland that cannot be reversed, and then failed in his bid to bring Owen back to Anfield when Newcastle's club-record bid blew Liverpool out of the transfer negotiations.
New £7m striker Crouch is at last available again after a hamstring injury and suspension ruled him out of the opening games of the season, but although he will be in the squad to face Spurs at White Hart Lane he is hardly match-fit.
All this brings Cissé firmly into the equation. He suffered an ankle injury for France in the win over the Faroe Islands last weekend but will find himself centre stage at Anfield in the coming weeks.Reuse content