Benitez is hopeful striker Fernando Torres will make a quicker-than-expected return from a thigh problem.
The club's record signing was withdrawn at half-time in Sunday's 1-1 draw against Arsenal - on his return after missing two matches with an adductor injury - and it was anticipated he would be out for a further three weeks.
"It is the same problem as before with Fernando. Hopefully he can be fit in two weeks," said the manager.
"We thought he was ready for the Arsenal game and during the match I asked him two or three times if he was okay because clearly he wasn't fit.
"He is not the sort of player who normally gets injuries and that's the reason he didn't feel what he had. That was the problem."
There was better news on Argentina midfielder Javier Mascherano, who hobbled through the closing stages of the draw against the Gunners with a bruised foot.
"Javier is okay. He trained today and so we've had good luck with him," Benitez added on Tuesday.
The Reds boss is still awaiting news on how long he will be without Spain midfielder Xabi Alonso, who is seeing a specialist about a broken metatarsal - his second of the season.
Centre-back Daniel Agger, who has not played since September 15 after also breaking a metatarsal, is still two weeks away from fitness.
"He is continuing to progress but with this kind of injury he needs time. I think we need to wait another 10-16 days," Benitez told the club's website.