"Steven has a hamstring strain and will be out for a fortnight, while Fernando has torn a cartilage in his right knee," the spokesman added.
"The injury will require surgery and he is expected to be sidelined for six weeks."
Benayoun - one of Liverpool's better players in what has been a desperately disappointing season so far - sustained a fractured rib in the 2-1 extra-time loss to Reading.
The trio will miss this weekend's match against Stoke and the subsequent Premier League encounters with Tottenham and Wolves but the Reds will hope to have Gerrard back in time to face Bolton on 30 January.
However, Torres's injury means he is set to miss next month's Merseyside derby against Everton and February's league matches with third-placed Arsenal and fourth-placed Manchester City.
Torres and Gerrard have struggled with injuries for most of the season, with both finding it difficult to hit top form as Liverpool's fortunes have waned.
The triple setback comes at a time when Benitez is under mounting pressure, with his side out of the Champions League and both domestic cups and down in seventh place in the Premier League.
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